15-2 JURASSIC BIVALVIA AND GASTROPODA 



mented with numerous fine spiral striae ; growth-lines forming a simple, shallow 

 arch the chord of which is moderately prosocline. (The aperture is not preserved 

 intact.) 



Holotype. No. G. 76414. The only specimen. 



Locality and horizon. Wilderri hill, 11 miles S.S.W. of Rahmu, N.E. Kenya ; 

 Upper Oxfordian, Seir Limestones. 



Remarks. When first illustrated, the shell now described was identified as 

 Pseudomelania valfinensis de Loriol (1887 : 141, pi. 14, fig. 7). Its spiral ornament, 

 which is clearly seen on parts of the holotype (although the surface is rather eroded), 

 resembles that of this European Lower Kimmeridgian species, but its spire is more 

 acute. 



Genus BOURGUETIA Terquem & Jourdy 1870 



Bourguetia saemanni (Oppel) 

 PL 25, figs. 8, 9 



1814a. Melania striata J. Sowerby : 101, pi. 47 (non Perry, 181 1). 



1853. Phasianella striata (Sow.) ; d'Orbigny : 322, pi. 324, fig. 15, pi. 325, fig. 1. 



1856. Phasianella saemanni Oppel : 507. 



1881. Bourguetia striata (Sow.) ; de Loriol : 31, pi. 8, fig. 5. 



1905. Bourguetia striata (Sow.) ; Dacque : 143. 



1909. Bourgouetia (sic) striata (Sowerby) ; Brosamlen : 284. 



1938. Bourguetia saemanni (Oppel) ; Cox : 60. 



i960. Bourguetia saemanni (Oppel) ; Joubert, pi. 12, figs, za, b. 



Material. Several specimens. 



Localities and horizons. Nchia stream, 2 miles W.N.W. of Mandawa, Tangan- 

 yika ; Callovian. Scarp face, eastern margin of Makoko plain, Bagamoyo hinter- 

 land, Tanganyika ; Upper Oxfordian. Low hills at Dusse, i\ miles S.E. of Rahmu, 

 N.E. Kenya ; Upper Oxfordian, Seir Limestones. Wilderri hill, 11 miles S.S.W. 

 of Rahmu ; same formation as the last. Hereri river crossing, 3 miles S. of Melka 

 Kunha, N.E. Kenya ; Kimmeridgian, Hereri Shales. 



Remarks. The occurrence in East Africa of this well-known large European 

 Jurassic shell, already recorded from the Kimmeridgian of Somaliland by Dacque, is 

 of great interest. In Europe the range of this species is from the Bajocian to the 

 Lower Kimmeridgian. 



Family COELOSTYLINIDAE 



Genus COELOSTYLINA Kittl 1894 



Coelostylina stockleyi sp. nov. 

 PL 26, figs. 3a, b, c 



Specific name. After Mr. G. M. Stockley, formerly Director of the Geological 

 Survey of Tanganyika. 



