FROM TANGANYIKA AND KENYA 83 



1874. ?Astarte lurida Sow. ; Dumortier : 175, pi. 40, figs. 2-4. 

 1905. Astarte elegans Sow. ; Benecke : 214, pi. 16, figs. 1-3 (non J. Sowerby). 

 1923. Astarte sublaevis d'Orbigny ; Ernst : 67, pi. 1, figs. 13a, b only (non d'Orbigny). 

 1935. Astarte subtetragona Miinster (with vars. brevis, krumbecki and subcarinata) ; Kuhn : 

 123, pi. 8, figs. 39a, b ; pi. 9, figs. 17a, b, 10a, b, 28a, b ; pi. 10, figs. 20a, b. 



Material. One specimen (no. LL. 35044). 



Locality and horizon. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ; 

 Upper Lias, Toarcian, Didimtu Beds. 



Remarks. Sowerby's holotype of Astarte lurida (B.M. (N.H.) no. 43082), from 

 the neighbourhood of Naunton, Gloucestershire, belongs to a widely distributed 

 Upper Liassic species. Abundant specimens from the Cotswold Cephalopod Bed 

 (Yeovilian) illustrate the variability of the species. There is complete intergrada- 

 tion between ovate shells in which the umbo is not terminal and the postero-dorsal 

 and posterior margins meet in a broad curve, and shells with a rectangular to rhom- 

 boidal outline in which the umbo is terminal and the margins mentioned meet in a 

 well-defined right or obtuse angle. There is also considerable variation in ornament, 

 some specimens having fairly regular concentric ribs and others irregular rugae. 

 These observations have led to the conclusion that A. subtetragona, based on rhom- 

 boidal specimens, should be regarded as a synonym of A. lurida. 



The specimen now recorded is 38-5 mm. long and thus of about the same size as 

 many specimens from the Cotswold Cephalopod Bed. Like the holotype, it is a 

 relatively ovate representative of the species. In England this species ranges from 

 the bifrons Zone of the Whitbian stage of the Upper Lias to the scissum Zone, near 

 the base of the Inferior Oolite. 



Astarte pulfreyi sp. nov. 

 PI. 12, figs. 12a, b, 13 



Specific name. After Dr. W. Pulfrey, lately Director of the Kenya Mines and 

 Geological Department. 



Diagnosis. Of large-medium size (length of largest specimen c. 33 mm.), sub- 

 orbicular with a quadrate tendency, length very slightly exceeding height, moderately 

 inequilateral ; inflation weak. Umbones at about anterior third of length, not 

 incurved, directed anteriorly, their outline continuous with postero-dorsal outline, 

 which is feebly convex and gently inclined, joining the feebly convex, sub vertical 

 posterior margin in an even curve or forming a rounded-off, obtuse angle with it ; 

 antero-dorsal outline feebly concave near umbo, steeply sloping ; anterior margin 

 rather strongly convex ; ventral margin strongly convex anteriorly, less convex 

 posteriorly, where it forms a rounded-off, obtuse angle with posterior margin. 

 Escutcheon and lunule narrow and shallow, almost absent. No ornament except 

 growth-rugae. Valve-margins denticulate internally. 



Holotype and paratypes. Holotype, no. LL. 35027 ; 4 paratypes. 



Locality and horizon. Didimtu hill, 2 miles S. of Bur Mayo, N.E. Kenya ; 

 Upper Lias, Toarcian, Didimtu Beds. 



