FROM TANGANYIKA AND KENYA 57 



Subgenus RADULOPECTEN Rollier 1911 

 Chlamys {Radulopecten) inequicostata (Young & Bird) 



PI. 7, ng. 5 



1822. Pecten inequicostatus Young & Bird : 236, pi. 9, fig. 7. 



1829. Pecten inaequico status Phillips : 129, pi. 4, fig. 10. 



1931a. Chlamys {Radulopecten) inaequico stata (Phillips) ; Arkell : 118, pi. 8, figs. 4-7 (also 



1935. pl- 52. ngs. i, 3). 

 i960. Chlamys {Radulopecten) cf. inaequistriata (Phillips) ; Joubert, pl. 7, fig. 4. 



Material. One specimen (no. L.92228). 



Locality and horizon. Dusse, i| miles S.E. of Rahmu, N.E. Kenya ; Upper 

 Oxfordian, Seir Limestones. 



Description. This specimen, which lacks the umbonal region and auricles and 

 is rather eroded, was originally about 67 mm. high and 50 mm. long. The right 

 valve has about six broad, depressed, rounded ribs which are separated by equally 

 broad intervals ; ribs and intervals are crossed by fine, closely spaced, rather 

 irregular, erect lamellae. The left valve has six ribs which are narrower than those 

 of the right valve and are separated by intervals most of which are slightly broader 

 than the ribs. One of the outer ribs on the anterior side bears short, spine-like 

 projections, but details of the ornament are not preserved on the others. 



Remarks. The African specimen differs from most examples of the species from 

 the Corallian Beds of England, the type occurrence, in the relative broadness of the 

 intervals between the costae of the right valve, but in occasional specimens from 

 England the intervals are just as broad. I see no reason, therefore, for separating 

 the African specimen from C. inaequicostata, which is also known from France, 

 Germany, Poland, and Switzerland. In Europe the species occurs in the Upper 

 Oxfordian and Lower Kimmeridgian. 



Chlamys {Radulopecten ?) kinjeleensis sp. nov. 

 Pl. 7, figs. 6a, b, ja, b 



Diagnosis. Shell small (height of holotype, the largest specimen, c. 13 mm.), 

 suborbicular, subequivalve, moderately convex. Ornament consisting of about 10 

 regularly arranged, broad, rounded radial costae, separated by slightly narrower, 

 rounded intervals ; ribs and intervals crossed by concentric threads (removed by 

 erosion except on a few small areas of the surface in the available specimens). Right 

 anterior auricle small, bearing two weak radial riblets ; posterior auricles rather 

 small, obtusely triangular. Byssal notch deep. 



Holotype and paratypes. Holotype, no. L. 5 1955, a right valve. Three para- 

 types (including nos. L. 52145 and LL.35098, ex B.P. Coll.). 



Localities and horizons. N. of Kinjele, 5 miles W. of Mtapaia, N. of Tenda- 

 guru, Tanganyika (type-locality) ; Upper Kimmeridgian, Nerinella Bed. Lilomba 



