8 , SOLARIUM. 



Genus EUOMPHALUS, Sowb., 1814. 



Shell depressed, planorbiform ; spire plane or concave; infe- 

 rior face widely umbilicated ; whorls in contact, convex at the 

 periphery, superior face carinated. Fossil, Paleozoic. 



Genus SCHIZOSTOMA, Bronn, 1835. 



Shell discoidal, planorbiform ; whorls more or less angulated 

 at the periphery, with a carina above and below; aperture 

 clasping, subtrigonal, lip sinuous, prolonged into a claw. Fos- 

 sil, Paleozoic. United States; Europe. S. Puzosii, Vern. 

 (Struct, and Syst. Conch., PL 65, f. 11.) 



Genus ECCYLIOMPHALUS, Portlock, 1843. 

 Shell subdiscoidal, planorbiform ; whorls few, rounded above, 

 flattened below, widely dissolute ; lip simple. Fossil, Paleozoic, 

 a few species. E. serpula, Kon. (Struct, and Syst. Conch., PL 

 65, fig. 20). 



Genus SOLARIUM, Lam., 1799. 

 Subgenus SOLARIUM (restricted). 

 S. PERSPECTIVUM, Linn. PL 2, figs. 18-21. 



Umbilical crenulations brown ; whorls spirally sulcate below 

 the suture, ribbed at the peripheiy, spirally sulcate and ribbed 

 above and below the periphery and near the umbilicus; color 

 purplish ash or light yellowish brown with interrupted or con- 

 tinuous brown bands next the suture and below the upper sulcus 

 and interrupted brown bands on the ribs about the periphery 

 and another near the umbilicus. Diam. 2*5 inches. 



Indian 0.; Pacific ; China to Australia. 

 S. trochleare and S.formosum, Hinds; S. zonatum and S. in- 

 cisum, Phil., are synonyms. 



Yar. AUSTRALIS, Phil. PL 2, figs. 20, 21. 



A smaller shell than the typical S. perspectivum color olive- 

 brown with a very light chestnut band at the suture, a white 

 band above and a very dark brown band below the upper sulcus, 

 rib above the periphery with an interrupted reddish brown band, 

 periphery and rib below it spotted with yellow or yellowish 

 brown ; umbilical crenulations yellowish or purplish brown. 



