1905. _Ostrea (Exogyra) olisiponensis_, P. Choffat, _Géol. Col. Portug. d’Afrique. II, Nouvelles données sur la zone littorale d’Angola_, p. 44, Pl. I., Figs. 4, 5.
_Remarks._—This species is represented by numerous examples, in a few of which the surfaces of the shell are well-preserved and show a few coarse ribs. Sharpe and other writers have noted the great variability in the ribbing of this species. The Nigerian specimens agree with the varieties which possess only a few ribs. Peron, Choffat, and Fortau have discussed fully the affinities and synonymy of _O. (Exogyra) olisiponensis_. This species is common in Northern Africa and Portugal; it occurs in the Cenomanian of Algeria, Tunis, Egypt, and Palestine; in Portugal it is found in both the Upper and Lower Turonian, as well as in the Cenomanian, wherever the deposits are of the marly facies. South of Nigeria this species has been discovered in the province of Angola.
_Localities._—Deba Habe and Gongila.
GERVILLIA (PSEUDOPTERA), sp.
Plate XX., Figs. 4–6.
There are several internal casts resembling in form _G. (Pseudoptera) anomala_ (Sowerby),[202] but there is no evidence to show whether radial ribs were present on the shell or not, and the species cannot be determined at present.
Specimens from the Cenomanian of the neighbourhood of Tebessa (Algeria) have been identified with Sowerby’s species by Coquand,[203] and Peron[204] states that it is abundant and well-preserved at that locality.
_Locality._—Awe.
ASTARTE AWENSIS, sp. nov.
Plate XX., Fig. 7.
_Description._—Shell rather small, moderately convex, with the postero- dorsal part somewhat compressed, outline subquadrate or subtriangular, very inequilateral. Anterior margin slightly concave; ventral margin convex; posterior margin short, truncated, forming an obtuse angle with the long, slightly convex postero-dorsal margin. Umbones pointed, rather prominent. Lunule large, ovate, smooth, with a sharp edge. Escutcheon large, deep, with a sharp edge. Ornamentation consists of about fourteen broad, prominent concentric ribs, which are marked by fine concentric lines. Length, 8·25; height, 7 mm.
_Affinities._—In the character of its ornamentation _A. awensis_ resembles several small species of _Astarte_ found in the Cretaceous rocks. It is more inequilateral, more elongate, and has the posterior margin more distinctly truncated than in _A. subsimilis_, J. Böhm.[205] In similar respects it differs from _A. griesbachi_, Woods,[206] from Pondoland.
_Remarks._—Numerous casts of this species occur in ferruginous nodules.
_Locality._—Awe.
LUCINA, sp.
Plate XX., Figs. 8, 9.
_Description._—Shell nearly orbicular, convex, slightly inequivalve; height and length nearly equal. Anterior and ventral margins rounded; posterior margin truncated, forming an obtuse angle with the straight or slightly convex postero-dorsal margin. Umbones rather prominent. Ornamentation consists of regular, concentric lamellar ribs separated by broad, flat interspaces which are marked by fine, concentric lines. Length, 11 mm.; height, 11·5 mm.
_Affinities._—In general form, and in the character of its ornamentation, this species resembles one of the varieties of _Lucina fallax_, Forbes, described by Stoliczka[207] from the Utatúr Group, but the umbones are more prominent, and the postero-dorsal angle is more distinct. It also resembles _L. saharica_, Quaas,[208] and some forms of _L. subnummismalis_, d’Orbigny.[209]
_Locality._—Kumberi.
CARDIUM, sp.
Plate XX., Fig. 10.
In the possession of numerous radial ribs and in the general form of the shell, some internal casts resemble _Cardium cenomanense_, d’Orbigny,[210] but the valves are less convex.
_Locality._—Awe.
CORBULA, sp.
Specimens of _Corbula_ resemble _C. elegans_, Sowerby,[211] in the character of their ornamentation, but the posterior part of the shell is more produced.
_Locality._—Awe.
GASTEROPODA.
PSEUDOMELANIA, sp.
Plate XXI., Fig. 1.
Several specimens of a small gasteropod resemble _Pseudomelania Pallaryi_, Peron and Fortau,[212] from the Cenomanian of Egypt, but they are of much smaller size, being from 8 to 13 mm. long. The surface of the shell is smooth, except for slightly curved growth-lines, and, on the base, spiral grooves.
_Locality._—Awe.
TURRITELLA, sp.
Plate XXI., Fig. 2.
A species of _Turritella_ resembles _T. Choffati_, Thomas and Peron,[213] from the Turonian of Tunis. The anterior part of each whorl is bent at an angle with the large flattened posterior part, and the ornamentation consists of four strong spiral ribs, one of which occurs at the angle, giving the appearance of a carina. On the later whorls the ribs become granular or tubercular. The ribs are much coarser than in _T. Choffati_.
_Locality._—Kumberi.
SEMIFUSUS AFRICANUS, sp. nov.
Plate XXI., Figs. 3–5.
_Description._—Shell subfusiform. Spire shorter than the last whorl, consisting of about five whorls. Whorls carinate, the carina being more or less distinctly nodular. Posterior part of the whorls flattened, much larger than the anterior part in the spire. Anterior part of last whorl convex. Ornamentation consists of narrow spiral ribs with flat interspaces crossed by growth-lines; on the later whorls the ribs become divided up into rows of elongated tubercles.
_Remarks._—This species, which is represented by several imperfect specimens, shows some resemblance to _Lagena nodulosa_, Stoliczka,[214] and _L. secans_, Stoliczka,[215] from the Ariyalúr Group, and also to _Serrifusus dakotensis_ var. _vancouverensis_, Whiteaves,[216] but possesses one carina only.
_Locality._—Awe.
CEPHALOPODA.
_Genus_—VASCOCERAS, P. Choffat.
(_Faune Crét. Portugal_, I., 1898, p. 51.)
VASCOCERAS NIGERIENSIS, sp. nov.
Plate XXI., Fig. 6; Plate XXII., Figs. 2, 3.
_Description._—Shell inflated, rounded, subglobose. Whorls thick, largely embracing; umbilicus deep, rather more than a third of the diameter of the shell, with nearly vertical walls, the umbilical margin subcarinate, without tubercles. Flanks curving gradually from the umbilical margin and not limited from the rounded periphery. Surface of shell with growth-rings.
Sutures: Saddles large, broad, and low; external saddle unsymmetrically divided and with small minor divisions; first lateral smaller than the external saddle, more rounded, less divided, with the outer margin sloping and the inner margin nearly perpendicular; second lateral saddle broad, only slightly divided. External lobe deeper than the first lateral lobe; the latter is small with one main division; second lateral lobe smaller, with two points.
(1) (2)
Diameter 88 93 mm.
Thickness 58 54
Height of last whorl 37 34
Width of umbilicus 30 33
(1) Reme. (2) Kunini.
_Affinities._—This species resembles the thicker forms of _V. durandi_ (Peron and Thomas),[217] but the walls of the umbilicus are steeper, the umbilical margin is without tubercles, and the external and first lateral saddles are broader and not so high. In general form, and in the absence of tubercles at the umbilical margin, _V. nigeriensis_ resembles _V. amierensis_, Choffat,[218] but the whorls embrace to a larger extent, and their sides are less flattened; there are also some differences in the suture. In the form of the umbilicus, and in the breadth of the saddles, this species resembles _V. harttiformis_, Choffat,[219] but the shell is much less thick. Another similar form but with a thicker shell, is _V. hartti_, Hyatt,[220] from Brazil.
_Localities._—Reme and Kunini.
VASCOCERAS GONGILENSIS, sp. nov.
Plate XXI., Fig. 7; Plate XXII., Fig. 1.
_Description._—Shell moderately inflated. Umbilicus less than a quarter of the diameter of the shell, with vertical walls and subcarinate margin. Flanks somewhat compressed. Periphery flattened. Inner whorls with strong ribs on the flanks and prominent tubercles at the umbilical margin and at the limit of the flanks and periphery; on the last whorl the ribs and tubercles gradually become obsolete.
Sutures: External saddle broad, subquadrate, with small divisions; first lateral saddle broad, rounded, divided unsymmetrically by a small lobe; second lateral saddle subquadrate; one small auxiliary saddle on the flanks. External lobe deep and larger than the first lateral lobe, which has only small divisions; second lateral lobe small, its lower margin with pointed divisions.
Diameter 108 mm.
Thickness 57 „
Height of last whorl 52 „
Width of umbilicus 24 „
_Affinities._—This species resembles _V. subconciliatum_, Choffat,[221] from the Turonian of Portugal, but the ribs and tubercles become obsolete at an earlier stage, the umbilicus is smaller, the divisions in the external saddle are less deep, the first and second lateral saddles are more rounded, and the first lateral lobe is narrower. _V. gongilensis_ also resembles some forms of _V. cauvini_, Chudeau.[222]
_Locality._—Gongila.
_Genus_—MAMMITES, Laube and Bruder.
(_Palæontographica_, XXXIII., 1887, p. 229.)
_Sub-genus_—PSEUDASPIDOCERAS, Hyatt.
(“Pseudoceratites of the Cretaceous,” _U. S. Geol. Surv. Mon._, XLIV., 1903, p. 106.)
MAMMITES (PSEUDASPIDOCERAS), sp.
Plate XXIII., Figs. 1, 2.
In the collection there is one specimen of _Mammites (Pseudaspidoceras)_; it resembles the form figured by Choffat[223] under the name _Acanthoceras_ (?), cf. _Footeanus_ (Stol.), from the Turonian of Portugal, but differs in having a smaller umbilicus and less distinct siphonal tubercles. The sutures are not shown in the specimen from Nigeria.
The Portuguese form differs from _A. footeanus_, Stoliczka,[224] by the absence of secondary ribs on the siphonal region of the inner whorls, and by the forward inclination of the ribs between the lateral tubercles and the siphonal tubercles.
Other allied species are _M. (Pseudaspidoceras) salmuriensis_ (Courtiller) var. _byzacenica_, Pervinquière,[225] from the Lower Turonian of Tunis, and _M. (Pseudaspidoceras) Pedroanus_ (White),[226] from Brazil.
_Locality._—Gongila.
_Genus_—HOPLITOIDES, A. von Kœnen.
(“Nachtrag Foss. Unter. Kreide Mungo in Kamerun,” _Abhandl. d. k. Gesellsch. d. Wiss. Göttingen, Math.-Phys. Kl., N.F._ Band 1, 1898, p. 53. Emended F. Solger, _Foss. Mungokreide in Kamerun_, 1904, p. 127; L. Pervinquière, _Études Pal. Tunis, I. Ceph._, 1907, p. 215.)
HOPLITOIDES NIGERIENSIS, sp. nov.
Plate XXIII., Fig. 3; Plate XXIV., Figs. 1–5. Text-figure 1.
_Description._—Shell discoidal, compressed, with truncated periphery. Whorls largely embracing, with the flanks slightly or moderately convex, the greatest convexity being at a short distance from the umbilical margin. Umbilicus small, or very small, about one-seventh of the diameter of the shell, its sides nearly perpendicular. Periphery usually rather broad, bounded on each side by a prominent rounded carina; the prominence of the siphuncle gives rise to a median rounded ridge between which and the carinas the shell is concave.
In fully-grown individuals the shell is smooth, but in smaller examples the flanks bear a few strong, rounded ribs, which curve slightly forwards near the periphery; the larger ribs start from the umbilical margin, and one or two smaller ribs may be intercalated on the flanks. Where the ribs join the carina the latter may become more or less distinctly tuberculate. Usually the ribs become obsolete when the shell reaches a diameter of about 50 mm., but occasionally they persist on larger individuals.
Sutures: External saddle broad, rather low, with a variable number of small divisions. First and second lateral saddles similar to, but distinctly smaller than the external saddle; each has usually some small divisions, but in some cases these are absent, and the saddle is then rounded. One or two auxiliary saddles may occur. External lobe deep, sometimes nearly as wide as the space between the two carinæ. First lateral lobe usually rather narrower and not so deep as the external lobe, with more or less numerous small divisions. The second lateral lobe is similar to, but smaller than the last.
(1) (2) (3) (4) (5) (6) (7) (8)
Diameter 110 95 84 67 68 62 57 44 mm.
Thickness 47 42 34 28 28 27 28 20 „
Height of last whorl 61 49 45 37 38 38 34 25 „
Width of umbilicus 15 15 10 10 7 6·5 8 6 „
(1–8) From Gongila.
Sutures of six specimens. Natural size.]
_Affinities._—This species appears to belong to the bicarinate group of _Hoplitoides_. In general form it resembles _H. munieri_, Pervinquière,[227] from the Lower Turonian of Tunis, but the whorls, are thicker, the flattened periphery is broader and shows a distinct siphuncular ridge. The sutures are similar to those of _H. munieri_, but are symmetrically placed, and the first lateral lobe is relatively narrow. The ribbing of the smaller specimens is similar to that of _Hoplites ingens_, v. Kœnen em. Solger.[228]
In general form, _H. nigeriensis_ is similar to _Heterotissotia neoceratoides_, Peron,[229] from the Lower Senonian of Algeria and the Upper Turonian of Tunis. Both possess a broad, flattened periphery with a keel on each side and a prominent siphuncular ridge, but in _H. neoceratoides_ the ribs are retained to a later stage. The figures given of the suture of Peron’s species are not satisfactory, and I am indebted to Dr. L. Pervinquière for comparing figures of the sutures of _Hoplitoides nigeriensis_ with the type of _Heterotissotia neoceratoides_ which is now in the Sorbonne. Dr. Pervinquière states that the differences in the suture are too great to allow of these two species being referred to the same genus.
_Remarks._—The sutures of _Hoplitoides nigeriensis_ vary considerably in appearance on account of the difference in the number and size of the small divisions of the saddles. A somewhat similar variation is seen in the sutures of _H. ingens_, v. Kœnen, em. Solger, and _H. munieri_, Solger. Variations also occur in the thickness of the whorls, the breadth of the periphery, the size of the umbilicus, and the period at which the ribs become obsolete. In one specimen, which is less thick than the other, the siphuncular ridge is absent.
This species is represented by numerous specimens, all of which are internal casts or have only a small portion of the shell preserved, and in nearly all cases the sutures are clearly exposed.
_Locality._—Gongila.[230]
PLATE XIX
T. A. Brock, del.
(The figures are of natural size unless the amount of enlargement is stated).
FIGS. 1–3. _Trigonoarca_, sp. Awe. 1, right valve; 2, dorsal view of the same; 3, hinge of left valve. (Page 276.)
„ 4. _Nuculana_, sp. Kumberi. Internal cast of left valve. × 11⁄2. (Page 276.)
„ 5–8. _Ostrea prælonga_, Sharpe. Gulani. 5, right valve; 6, 8, right valves with umbo of left valves; 7, left valve. (Page 277.)]
PLATE XX
T. A. Brock, del.
FIGS. 1–3. _Ostrea (Exogyra) olisiponensis_, Sharpe. Deba Habe. Left valves. (Page 277.)
„ 4–6. _Gervillia (Pseudoptera)_, sp. Awe. Internal casts. 4, 5, left valves; 6, right valve. (Page 278).
„ 7. _Astarte awensis_, sp. nov. Awe. Right valve, drawn from a wax impression of an external cast, × 11⁄2. (Page 279.)
„ 8, 9. _Lucina_, sp. Kumberi. 8, right valve; 9, dorsal view of the same, × 11⁄2. (Page 279.)
„ 10. _Cardium_, sp. Awe. Internal cast of right valve. The marginal part of the valve is imperfect. (Page 280.)]
PLATE XXI
T. A. Brock, del.
FIGS. 1. _Pseudomelania_, sp. Awe. × 11⁄2. (Page 280.)
„ 2. _Turritella_, sp. Kumberi. × 11⁄2. (Page 281.)
„ 3–5. _Semifusus africanus_, sp. nov. Awe. 3, drawn from a wax impression of an external cast; 4, portion of the ornamentation of 5, × 6. (Page 281.)
„ 6. _Vascoceras nigeriensis_, sp. nov. Reme. (Page 281.)
„ 7. _Vascoceras gongilensis_, sp. nov. Gongila. Internal cast. (Page 282.)]
PLATE XXII
T. A. Brock, del.
FIGS. 1._Vascoceras gongilensis_, sp. nov. Gongila. Siphonal view of Fig. 7, Plate XXI. (Page 282).
„ 2, 3. _Vascoceras nigeriensis_, sp. nov. Kunini. Two views of the same specimen. (Page 281.)]
PLATE XXIII
T. A. Brock, del.
FIGS. 1, 2. _Mammites (Pseudaspidoceras)_, sp. Gongila. Two views of the same specimen. (Page 283.)
„ 3. _Hoplitoides nigeriensis_, sp. nov. Gongila. (Page 284.)]
PLATE XXIV
T. A. Brock, del.
FIGS. 1–5. _Hoplitoides nigeriensis_, sp. nov. Gongila. 1, siphonal view of Fig. 3, Plate XXIII; 4, siphonal view of Fig. 3. (Page 284.)]
[Footnote 196: The occurrence of Turonian fossils at this locality has been recorded by G. C. Crick, _Geogr. Journ._, Vol. XXIV., 1904, p. 522, footnote 1.]
[Footnote 197: Dames, _Sitzungsber. Ges. nat. Freunde, Berlin_, 1887, pp. 69, 137.]
[Footnote 198: Guillemain and Harbort, “Profil der Kreideschicht. am Mungo,” _Abhandl. d. k. preuss. geol. Landesanst. N.F._, Heft 62, 1909, p. 405.]
[Footnote 199: Stoliczka, _Cret. Fauna S. India_, 1871, p. 353, Pl. XVIII., Figs. 12, 14; Pl. XIX., Figs. 2, 3; Pl. XX., Figs. 2, 8, 9, 10.]
[Footnote 200: _Mon. Cret. Lamell. England_, Vol. II., 1904, p. 31, Pl. V., Figs. 16–20.]
[Footnote 201: _Mon. Aptien de l’Espagne_, 1865, p. 166, Pl. XXVI., Figs. 1, 2.]
[Footnote 202: For figures see Woods, _Mon. Cret. Lamell. England_, Vol. II., 1905, p. 64, Pl. IX., Figs. 2–4. Compare also d’Orbigny, _Pal. Franç. Terr. Crét._, Vol. III., 1846, p. 478, Pl. CCCXCII., Figs. 1–3. When describing this species I overlooked Guéranger’s statement that he had seen specimens showing ligament pits; from the presence of those pits it is evident that this species cannot belong to _Pteria_. It seems probable that _Pseudoptera_ should be regarded as a sub-genus of _Gervillia_. Guéranger, _Album Paléont. de la Sarthe_, 1867, pp. 17, 20, Pl. XXII., Figs. 9, 10; Pl. XXV., Figs. 10, 11.]
[Footnote 203: _Géol. et Pal. de Constantine_, 1862, p. 292.]
[Footnote 204: Peron, _Moll. Foss. Terr. Crét. Tunisie_, 1890, p. 238.]
[Footnote 205: “Kreidebild. des Fürbergs u. Sulzbergs,” _Palæontographica_, XXXVIII., 1891, p. 74, Pl. III., Fig. 8.]
[Footnote 206: _Ann. S. African Mus._, IV., 1906, p. 300, Pl. XXXV., Figs. 18, 19.]
[Footnote 207: _Palæont. Indica, Cret. Fauna S. India_, III., 1871, p. 256, Pl. XIV., Fig. 7.]
[Footnote 208: _Palæontographica_, XXX., 2, 1902, p. 214, Pl. XXIV., Fig. 7.]
[Footnote 209: _Ravn, Mollusk. Danmarks Kridtafl. I. Lamellibr._, 1902, p. 129, Pl. IV., Fig. 21.]
[Footnote 210: _Pal. Franç. Terr. Crét._, III., 1844, p. 37, Pl. CCXLIX, Figs. 5–9.]
[Footnote 211: Woods, _Mon. Cret. Lamell. England_, Vol. II., 1908, p. 216, Pl. XXXIV., Figs. 23–28.]
[Footnote 212: _Bull. Institut Égypt._, Ser. 4, Vol. VI., 1903, p. 270, Pl. I., Fig. 22.]
[Footnote 213: _Moll. Foss. Crét. Tunisie_, 1889, p. 47, Pl. XIX., Figs. 13, 14.]
[Footnote 214: _Cret. Fauna S. India_, Vol. II., 1867, p. 137, Pl. XI., Fig. 18.]
[Footnote 215: _Ibid._, p. 138, Pl. XI., Figs. 19, 20.]
[Footnote 216: _Mesozoic Fossils_, Vol. I., 1879, p. 119, Pl. XV., Fig. 5. Compare also Woods, _Ann. S. African Mus._, Vol. IV., 1906, p. 324, Pl. XL. Figs. 5, 6. Newton, _Trans. Roy. Soc. S. Africa_, Vol. I., 1909, p. 28, Pl. IX., Fig. 6.]
[Footnote 217: _Moll. Foss. Crét. Tunisie_, 1889, p. 27, Pl. XVIII., Figs. 5–8. Peron, _Amm. Crét. supér. Algérie_, 1896–7, p. 44, Pl. IV., Fig. 1; Pl. V., Fig. 1; Pl. XVII., Fig. 5. Pervinquière, _Paléont. Tunisienne, Ceph. secondaires_, 1907, p. 332, Pl. XXI., Fig. 1. _V. Douvillei_, Choffat, _Faune crét. Portugal_, Vol. I., 1898, p. 59, Pl. X., Fig. 6; Pl. XI., Figs. 2–5; Pl. XXI., Figs. 13–16.]
[Footnote 218: Choffat, _ibid._, p. 61, Pl. XII., Figs. 1, 2; Pl. XIII., Figs. 1, 2; Pl. XXI., Figs. 17–21.]
[Footnote 219: _Ibid._, p. 61, Pl. XII., Fig. 3; Pl. XIII., Figs. 3–6; Pl. XXI., Figs. 22–24.]
[Footnote 220: “Contrib. Paleont. Brazil,” _Archiv. Mus. Nac. Rio de Janeiro_, VII., 1887, p. 226, Pl. XIX., Figs. 1, 2; Pl. XX., Fig. 3. Hyatt, “Pseudoceratites of the Cretaceous,” _U. S. Geol. Survey, Mon._, XLIV., 1903, p. 103, Pl. XIV., Fig. 16.]
[Footnote 221: _Faune crét. Portugal_, Vol. I., 1898, p. 64, Pl. XV., Figs. 1–3; Pl. XVI., Fig. 4; Pl. XXII., Figs. 28–31.]
[Footnote 222: “Ammonites du Damergou (Sahara meridional),” _Bull. Soc. géol. de France_ (4), IX., 1909, p. 68, Pls. I., II., III.]
[Footnote 223: _Faune crét. Portugal_, Vol. I., 1898, p. 66, Pl. XVI., Figs. 9, 10; Pl. XXII., Figs. 3, 4.]
[Footnote 224: _Palæont. Indica, Ceph. Cret. S. India_, 1864, p. 101, Pl. LII., Figs. 1, 2. Kossmat, “Südindische Kreideformat,” _Beitr. Pal. Geol. Osterr-ungarns u. d. Orients_, XI., 1897, p. 20. Petrascheck, “Amm. sächsich. Kreideformat., _ibid._, XIV., 1902, p. 144. Pl. IX., Fig. 1.]
[Footnote 225: _Études Paléont. Tunisienne, I. Ceph. Second._, 1907, p. 315, Pl. XIX., Fig. 1.]
[Footnote 226: “Contrib. Paleont. Brazil,” _Archiv. Mus. Nac. Rio de Janeiro_, VII., 1887, p. 212, Pl. XXII., Figs. 1, 2.]
[Footnote 227: _Études Pal. Tunis, I, Ceph._, 1907, p. 217, Fig. 83, Pl. X., Figs. 1, 2.]
[Footnote 228: Solger, _Foss. Mungokreide in Kamerun_, 1904, p. 137, Pl. V., Figs. 8, 9.]
[Footnote 229: _Amm. Crét. supér. de l’Algérie_, 1897, p. 82, Pl. XVI., Figs. 9, 10; Pl. XVIII., Fig. 20. Pervinquière, _Études Pal. Tunis, I., Ceph._, 1907, p. 379, Pl. XXIII., Fig. 7.]
[Footnote 230: Specimens of _Hoplitoides_ have also been found at Reme, but are not sufficiently well-preserved for specific identification. An imperfect Ammonite from Kumberi resembles in the form of its shell and in the general character of the sutures _Coilopoceras lesseli_, Brüggen, _Neues Jahrb. für Min._, etc., Beil.-Band XXX., 1910, p. 734, Plate