TRKMATOniSCrs, CIMOMIA, ETC. 217 



Siilii^ciiiis Temnocheilus, McCoy. 



Shell carinateil, with an open, conical umbilicus. 

 Five species. Oarb. limestojie. 



T. BIANOULATUS, Sowl). PI. '.IS, fig. .'S03. 



Sul)geinis Trematodiscus, Meek and Wortheii. 



Like Temnocheilus^ but dorsal or outer side of whorls witli 

 revohdng angles and sulci, and frequently, reA^olving striiv 



Carboniferous. Europe: America. 

 T. TRisULCATUs, Meek and Worthen. PI. ',18. fig. n04 o, b. Sub- 

 carboniferous. Rockford. Inch 



Siihgtnus Cimomia, Com-iul. 



Septa sinuous, double waved or sigmoid, numerous; siphon 

 small, central. 

 N. BuRTONi, Galeotti. Lower Eocene. 



Suli,:ioiius Hercoglossa, Conrad. 



Septa angular and linguiform ; apex of the angle or tongue- 

 shaped lobe not contiguous with the adjacent septum ; siphon 

 large or moderate, situated within the centre, or between the 

 middle and the inner margin, and not dorsal or funnel-shaped, 

 but tubular and gradually tapering. 



Eocene. Cret. Europe ; America. 



A very doubtful group, as C'onrad includes species having 

 respectively the characters of Aluria and of Nautilus .- the 

 type species, however, N. 07'biciilafus of Tuomey, has not been 



figured. 



Subgenus Pseudonautilus, Meek. 



Differs from Hercoglossa in the septa being provided with a 

 well-defined peripheral and antiperipheral lobe, and the sii)hunc]e 

 placed near the outer margin. 



Nautilus Geinitzt, Oppel. 



Subgenus Cryptoceras, d'Orb. 



Planorbiform ; septa arcuated, Avithout lobes or sinuosities; 

 siphon dorsal. 



Two species. Devonian, Carboniferous. Europe. 



C. SUBTUBERCULATUS, d'Orb. PI. 9<S, fig. r>{)4. 



28 



