88 JURASSIC BIVALVIA AND GASTROPODA 



Remarks. Specimens of this species from the Spiti Shales were described very 

 fully by Holdhaus, but it is not clear why he preferred Oppel's specific name to the 

 earlier one of Sowerby. Sowerby's type and the specimen from the Spiti Shales 

 figured by Salter are both in the British Museum (Natural History) , where there are 

 also numerous topotypes from Cutch. The species is characterized by its strongly 

 inequilateral cuneiform shape and its strongly convex postero-dorsal outline, which in 

 many specimens rises appreciably above the umbo before beginning to slope steeply 

 downwards to join the low posterior margin in an uninterrupted curve. The 

 earlier growth stages are ornamented with well separated, regular, angular concentric 

 folds, which later are replaced by irregular rugae. This is the first record of the spe- 

 cies from East Africa. The specimens recorded are up to about 44 mm. long and 

 quite typical as regards shape and ornament. 



In Cutch this species occurs most commonly in the Callovian athleta Beds and 

 Oxfordian Dhosa Oolite. Ill-preserved specimens which appear to be referable to it 

 occur in the Callovian Chari beds and also in the Upper Oxfordian. 



Astarte sowerbyana Holdhaus 

 PI. 13, figs. 6a, b 



1840c. Astarte major J. de C. Sowerby, pi. 61, fig. 1 and explan. (non Astarte elegans major 



Zieten). 

 1913. Astarte sowerbyana Holdhaus : 443, pi. 99, figs. 12, 13, 15 ; pi. 100, fig. 1. 

 1933. Astarte krenkeli Dietrich : 40, pi. 4, figs. 62, 64, 66. 



Material. Three specimens (including nos. L. 52688, LL. 35120), partly ex B.P. 

 Coll. 



Localities and horizons. Lihimaliao creek, Mandawa area, Tanganyika ; 

 Upper Oxfordian. N. of Kipande, also 1 mile N.W. of Tendaguru hill, Tanganyika ; 

 Upper Kimmeridgian, Nerinella Bed. 



Remarks. This species differs from A . unilateralis in its more ovate outline and 

 larger size, although the difference in size is not so marked in the specimens from 

 the Spiti Shales described by Holdhaus as in those from India and East Africa. In 

 the African specimens, as in those from India, there is some variation in the relative 

 elongation of the shell. Sowerby's type specimen of A . major, which is in the British 

 Museum (Natural History), is a relatively elongate shell and very similar to Dietrich's 

 type of A. krenkeli. It is strange that Dietrich made no reference to Sowerby's 

 species. In early stages of growth A. sowerbyana, like A. unilateralis, bears con- 

 centric folds. In later stages these are replaced by rather distant concentric undula- 

 tions in some specimens and by irregular corrugations in others. 



In Cutch this species occurs at several localities in the Upper Oxfordian (Argovian) 

 Astarte Bed, and it reappears in the Tithonian of Moondan and elsewhere. 



Astarte episcopalis de Loriol 



1897. Astarte duboisi d'Orbigny ; de Loriol : 88, pi. 12, fig. 13 (non d'Orbigny). 

 1901. Astarte episcopalis de Loriol : 72, pi. 5, figs. 1, 2. 



