BIVALVIA. 77 



AsTARTE FiMBRiATA, fraIfon,MSiS. Tab. XL, figs. 31-, 34 a. 



Testa transversa, ovata, s>'hdeprcssa, iimhonihus aniemedianis parvis, margine cardi- 

 nali elonyato, siibrecto, ohliquo, acuto ; lunula inofjna elliptica ; lateribus costulis concen- 

 tricis acutis, elevatls subdistantibus ; afate progrediente crebrioribus et irregularibus 

 instructis. 



Shell transverse, ovate, somewhat depressed ; umbones small, depressed, curved forwards; 

 hinge-margin lengthened, nearly straight, its margin acute and rendered fimbriated by 

 the acute, projecting extremities of the costae, which are elevated, concentric, distantly 

 arranged, and regular in the young shell, but more closely arranged and irregular in 

 specimens of adult growth ; the Innule is large, elliptical, its margins acute. 



Allied to A. depressa, Goldf., compared with which the umbones are less prominent 

 and more ol)lique, the hinge-border more lengthened, the costse more elevated and fewer ; 

 the convexity of the valves is also greater. The test is thinner than is usual with this 

 genus. 



Occasionally a small and ill-preserved specimen has been found in the Great Oolite of 

 Minchinhampton, and mistaken for A. minima, Phil. ; the costa) in the latter shell are more 

 obtuse and more closely arranged, the general figure being more orbicular. 



Geological Positions and Localities. The Forest Marble of Farleigh and the Great 

 Oolite of Bussage, near Bisley Common. 



AsTARTE? iGNOTA, Lgc. Tab. XL, fig. 10. 



Testa subovata, subdepressa,postice truncata,inferne etpostice oblique subangulata, um- 

 bonibus aniemedianis acuminatis, lunula parva, superficie, plicis incrementi numerosis, deli- 

 cate instructis. 



Shell subovate, subdepressed posteriorly, with a truncated extremity to the 

 hinge-border and with an oblique angle proceeding from the umbo to the inferior- 

 posterior border ; umbones antero-mesial, pointed, and curved forwards ; lunule slightly 

 impressed ; the surfaces of the valves with delicate, irregular, numerous plications of 

 growth. 



The hinge not having been seen, the genus is rather doubtful; possibly it may be a 

 Cgpricardia. 



Geological Position and Locality. The Forest Marble of Laycock ; in the collection of 

 W. Walton, Esq. 



