\7i JURASSIC BIVALVIA AND GASTROPODA 



Genus PSEUDONERINEA de Loriol 1890 



Pseudonerinea clio (d'Orbigny) 

 PI. 30, figs. 5, 6 



18506. Chemnitzia Clio d'Orbigny : 2. 



1851. Chemnitzia Clio d'Orbigny : 66, pi. 249, figs. 2, 3. 



1 861. Chemnitzia Clio d'Orb. ; Thurmann & Etallon : 87, pi. 6, fig. 26. 



1867a. Pseudomelania Clio (d'Orbigny) ; de Loriol : 14, pi. B, fig. 1. 



1887. Pseudomelania Clio (d'Orbigny) ; de Loriol : 139, pi. 14, figs. 5, 6. 



1894a. Pseudonerinea Clio (d'Orbigny) ; de Loriol : 42, pi. 3, figs. 5, 6. 



1898. Pseudonerinea Clio (d'Orbigny) ; Cossmann : 10, pi. i, figs. 11, 12, 16. 



191 1. Pseudomelania aff. Clio (d'Orbigny) ; Blaschke : 166, pi. 4, fig. 6. 



Material. Six specimens (including nos. GG. 10329-31), mostly imperfect. 



Locality and horizon. \ mile E. of Nangororo, Tanganyika ; Upper Kim- 

 meridgian. 



Remarks. The largest of the specimens now recorded is about 57 mm. high. 

 The specimens agree quite well with European ones in the general form of the shell 

 and the relative height of the almost flat whorls. In one specimen the anterior out- 

 let of the aperture, which undercuts the columella, is well seen, but its canal-like 

 appearance is intensified by the fact that the basal lip is broken away. In the fig- 

 ures of P. clio published by d'Orbigny and by Thurmann & Etallon the anterior margin 

 of the aperture is restored, incorrectly, as entire and evenly rounded. Cossmann 

 describes the aperture of P. clio as " largement sinueuse a la base " and the columella 

 as " se terminant en pointe un peu inflechie contre la sinuosite anterieure de 

 l'ouverture, sans former de bee avec le contour superieur [i.e. the basal margin]. " 

 De Loriol (1894a : 42, pi. 3, fig. 5), however, figures a specimen with an anterior out- 

 let very much like that of the form now described and comments upon it. Cossmann 

 (1898 : 4) would refer species with a canal-like outlet to Fibula rather than to Pseudo- 

 nerinea, but in typical species of Fibula the shell is much less slender than in forms 

 such as that now recorded. One of the specimens has been sectioned and shown to 

 be without internal folds, as in all species of Fibula and Pseudonerinea. In Europe 

 this species occurs in coralline beds of the Kimmeridgian stage. 



Genus TROCHALIA Sharpe 1850 



Trochalia depressa (Voltz) 

 PI. 29, fig. 7 



1835. Nerinea depressa Voltz : 425. 



1836. .Nerinea depressa Voltz ; Bronn : 549, pi. 6, figs. 17a, b. 



1850. Trochalia depressa (Voltz) ; Sharpe : 107. 



1 85 1. Nerinea depressa Voltz ; d'Orbigny : 104, pi. 259 (as N. umbilicata). 

 1861. Nerinea depressa Voltz ; Thurmann & Etallon : 97, pi. 8, fig. 42. 

 1869. Cryptoplocus depressus (Voltz) ; Gemmellaro : 42, pi. 6, figs. 9-11. 



1869. Cryptoplocus umbilicatus (d'Orb.) ; Gemmellaro : 43, pi. 2 bis, figs. 18, 19. 

 1874. Trochalia depressa (Voltz) ; de Loriol : 312, pi. 7, fig. 2. 

 1886. Trochalia depressa (Voltz) ; de Loriol : 115, pi. 11, figs. 10, 11. 



1898. Cryptoplocus depressus (Voltz) ; Cossmann : 158, pi. 11, figs. 33, 34 : pi. 12, figs. 3, 4, 7, 

 11, 12. 



