Eocene Shells from Nigeria. 89 



Gastropoda. 

 Calyptrcca nigeriensis^ sp. n. (PI. V. fig. 3.) 



This form of Calyptrcea is represented bj a natural lime- 

 stone-cast exhibiting fairly good external characters. It is a 

 subglobular form, and possesses four slightly rounded, de- 

 pressed whorls, the penultimate being of considerable depth 

 (17 mm.) in front, whilst the last is fractured and imperfect. 

 The surface of the later whorls is ornamented with numerous 

 straight, longitudinal, radial riblets, wiiich are fine at first, 

 but wiiich afterwards become coarser, being thickest near the 

 sliglitly impressed suture. Tliese radial lines show certain 

 obscure asperities which iiidicate the former presence of minute 

 spines. The apical surface is apparently smooth. 



Dimensions. Summit to margin of basal fracture 4-4 mm. ; 

 transverse diameter 50 mm. 



This species appears to show a relationship to C. aperla 

 of Solander, from the European Eocenes. It is, however, of 

 less conical form, more spreading and depressed in its volu- 

 tions, and with a more regular and generally coarser sculpture; 

 the sculpture of G. aperta being of a vermicular character, 

 and considerably more minute in the disposition of its spines. 

 On the matrix of this specimen occurs the remnant of an 

 Echinoid plate, with some prominent tubercles which may 

 represent the genus Rhahdocidaris referred to in De Lap- 

 parent's account of fossils from this area of Africa. 



Loc. Kalfu-Tamaskie. 



Collector. Colonel Elliot. 



Volutilithes cithara, Lamarck. (PI. V. fig. 2.) 



Voluta cithara, Lamarck, Hist. Nat. Aniin. sans Vert. 1822, vol. vii. 



p. 348; Deshajes, Desc. Coq. Foss. Paris, 1835, vol. ii. pi. xc. 



ligs. 11, 12, p. 681 ; J. de C. Sowerby, Mineral Conchology, 1813, 



vol. vii. pi. 625, figs. 1, 2, 3 ; id. Dixon's ' Sussex,' 1850, pi. y. lig. 17, 



p. 106; F. E. Edwards, Mon. Pal. Soc. 1854, pi. xxiii. fig. 6, p. 176; 



Archiac, Desc. Anim. Foss. Xumraiilitique I'lnde, 1854, pi. xxxii. 



figs. 4, 5, p. 325 ; Zittel, " Libys<;hen Wiiste," Paleeontographica, 



1883, vol. XXX. p. cviii. 

 Volutilithes cithara, Cossmann, Ann. Soc. R. Mai. Belgique, 1889, 



vol. xxiv. p. 105. 



Consists of a limestone-cast of a small compressed example 

 of a Volutiform shell, resembling in every way the V. cithara 

 figured by Archiac irom India, especially his figure 4, 

 which is likewise a cast. It exhibits the distant longitudinal 

 costae with the smooth concave interspaces so characteristic of 

 the species. The specimen is very much worn, so that no 

 oblique spiral lines are observable at the anterior end. This 



