AMUSIUM. 



121 



The following list of the fossils found with 8. carboniferwm will be of interest : 



Brachiopoda : 



Atliyris ambigua. 



Chonetes Lagncssin u ia. 



Discina nitida. 



Lin git la m ytiloides. 



Orthis resupinata ? 



Prui] u rhis semireticulatus. 

 Lamellibranchiata : 



Pseudamusiuni fibrillosum. 



Pterinopecten papyraceits. 



Posidoniella, sp. nov. 



P. hvvis. 



Sync yd one m a carboniferwm. 



Ctenodonta laevirostris. 



Nucula gibbosa. 



Nuculana Sharmani. 



N. acuta. 



Schizodus antiquus. 



Solenomya primpeva. 



Cephalopoda : 



Gastrioceras carbonarium. 



GlypMoceras diadema. 



Dimorphoceras Gilbertsoni. 



Ejilt ippioceras bilobatum. 



Pleuronavtilus armatus. 



Stroboceras sulcatum ? 



Orthoceras, sp. 



0. sulcatum ? 

 Gasteropoda : 



Loxonema, sp. 



Macrocheilina, sp. 



Raphistoma junior. 

 cf. Tii rbonellina formosa. 

 cf. Bellerophon (EupJiemus) Urei. 



ECHINODERMATA : 



Archn'ocidaris (spines and plates). 

 Crinoid ossicles. 

 Pisces : 



Listracauthus, Edestus, etc. 



Many of these species are dwarfed. 



8. carboniferwm is much narrower than 8. Sow erbyi, and T think quite a distinct 

 species, and not merely dwarfed. I have been able to see the interior, which in 

 every detail is similar to that of 8. Sowerbyi, but the valve is markedly orna- 

 mented with fine, close, concentric lines. 



Genus Amusium, Bolten (ex Klein). 



Amusium, Bolten, 1798. Mus. Bolten, pt, 2, p. 165. 



Generic ('Infractors. — Shell ovato-triangular, with broad anterior and posterior 

 flanges, flattened. Umbones small. Ears small, triangular, elevated. 



Interior. — Marked with broad radiating sulci. 



Exterior. — The shell is ornamented with narrow, regular, concentric lines, so 

 fine in some shells as to be almost smooth; occasionally broad, radiating, almost 

 obsolete ribs are seen. 



Distribution. — Carboniferous to Recent. 



Observations. — Hitherto Carboniferous shells, which had been referred to 

 Amusium by M'Coy, with a query by R. Etheridge, jun., have been those 

 which possess smooth, non-ribbed, internal surfaces; and, until the present, qo 

 speeies with this character have been recognised from Carboniferous rocks. It is 



