360 MANUAL OF THE MOLLTTSCA. 



Synonyms, Creseis, Forbes.* Pugiunculus, Barr. 



Shell straight, conical, tapering to a point, back flattened, 

 aperture trigonal. Length, 1-8 inches. 



Fossil, 40 species. Palreozoic. North America, Britain, New 

 South Wales. ? Permian. 



Pterotheca, Salter. 



Typcy P. transversa, Portlock, 3 species. Lower Silurian ; 

 Ireland, "Wales, Canada. 



Shell bi-lobed, transversely oval, with a dorsal keel projecting 

 slightly at each end ; ventrg,l plate small fcriap^ular. 



? CoNULAHiA, Miller. 



Etymology, comilus, a little cone. 



Type, 0. quadrisulcata, Fig. 144. 



Shell four-sided, straight, and tapering, the angles 

 grooved, sides striated transversely, apex partitioned 

 off. 



Fossil, 40 species. Silurian — Carb. North America, 

 Europe, Australia. 



Sub'.genus. Coleoprion (gracilis), Sandberger ; 

 Devonian. Germany. Shell round, tapering, sides 

 obliquely striated, striae alternating along the dorsal 

 line. 

 Fig' Xii-t EuEYBiA, Eang. 1827.^ 



Etymology, Euryhia, a sea-nymph. 



Synonym, Theceurybia, Bronn. 



Example, E. Gaudichaudi, PI. XIV., Fig. 37 (after Huxley). 



Animal globular ; fins narrow, truncated, and notched at the 

 ends, united ventrally by a small lobe (metapodium) ; mouth 

 with two elongated tentacles, behind which are minute eye- 

 peduncles and a two-lobed rudimentary foot {mesopodium) ; body 

 enclosed in a cartilaginous integument, with a cleft in front, 

 into which the locomotive organs can be retracted. Lingual 

 teeth, 1.0.1. 



The animal has no proper gill, but Mr. Huxley has observed 

 two ciliated circles surrounding the body, as in the larva of 

 Pneumodermon. 



Distribution, 4 species, Atlantic and Pacific. 



Sub-genus. Psyche, Eang. (Halopsyche, Bronn.) P. globulosa, 



» Creeds Sedgwicki, Forbes, is an orthoceras with very thin septa, belonging to the 

 Bame group with (Conularia) teres, Sby. TentacuUtes, Schl, is annellidous. (Salter.) 



t Carboniferous limestone, Brit. Belgium. 



t This name had been previously employed for four different genera of plants and 

 OiLimals. 



