116 CRETACEOUS LAMELLIBRANCHIA. 



Ornamentation consists of numerous, rather strong, narrow, concentric ribs 

 which are somewhat irregular. 



Hinge-plate broad, triangular. In the left valve two strong cardinal teeth and 

 one lateral at the margin of the lunule. Teeth of right valve not seen. Margins 

 of valves strongly crenulate. 



Measurements : 



(1) (2) (3) (4) 



Length 57 . 51 . 51 44 mm. 



Height . 59 . 56 . 47 . 39 „ 



(1-4) Claxby Ironstone, Benniworth Haven. 



Affinities. — This species is allied to Astarte Saemanni, de Loriol, 1 of which good 

 specimens are found in the Portland Sands of Swindon. In some cases the resem- 

 blance is very close, but generally the umbones are more prominent, the antero- 

 dorsal margin relatively longer, and the valves more convex in A. Ixvis than in 

 A. Ssemanni. 



A. Buchi, Romer, 2 is apparently allied to A. Isevis, but is distinguished by the 

 greater anterior curvature of its umbones. A. gigantea, Leymerie, 3 is less inequi- 

 lateral and more elongate than A. Isevis. 



Remarks. — Most of the examples of this species have been obtained from the 

 Claxby Ironstone. Only two have been seen from the Speeton Clay, one being in 

 the Leckenby Collection (Sedgwick Museum), the other in Mr. Lamplugh's Col- 

 lection ; these appear to agree with the larger example of Astarte Isevis figured by 

 Phillips (fig. 19). 



Types. — The type, from the Speeton Clay, appears to be missing. 



Distribution. — Claxby Ironstone (zone of Belemnites lateralis) of Benniworth 

 Haven. Speeton Clay of Speeton. 



Astarte (Eeiphyla) striata, Sowerby, 1826. Plate XVII, figs. 2-7. 



1826. Astarte striata, J. de C. Sowerby. Min. Conch., vol. vi., p. 35, pi. dxx, 



fig. 1. 

 1836. — concinna, J. de C. Sowerby. Trans. Geol. Soc, ser. 2, vol. iv, 



pp. 239, 341, pi. xvi, fig. 15. 

 1842. — F. Eomer. De Astartarum G-enere, p. 21. 



1 De Loriol and Pellat, ' Portlandien de Boulogue-sur-mer ' (1866), p. 68, pi. vi, fig. 9. E. G. 

 Skeal and V. Madsen, ' Jur. Neoc. and Gault Boulders in Denmark' (1898), p. 123, pi. iii, fig. 2. 



2 ' De Astartarum G-enere' (1842), p. 20, fig. 4. Pictet and Renevier, ' Foss. Terr. Aptien' (1856), 

 p. 85, pi. x, fig. 1. 



3 For references sec Pictet and Campiche, ' Terr. Cret. Ste. Croix' (1866), p. 298. 



