322 BELLEROPHONTID^. 



and it lacks the sharp tooth on the pillar with strongly marked 

 sinus above and below it, of that genus. 



Specimens were obtained by the Challenger expedition at 

 depths varying from 390 to 1900 fathoms. 



Family BELLEROPHONTID^. 



Shell globular, nautiliform, symmetrically convoluted ; per- 

 iphery carinated or sulcated, ending in a slit of the middle portion 

 of the outer lip. 



A large group of palaeozoic fossils, the natural relations of 

 which are very doubtful. They have been placed with the Cepha- 

 lopoda, Bullidse, Pteropoda, etc., but the slit shell appears to 

 indicate closer affinities with the Pleurotomariidse, and the best 

 modern systematists place them in the vicinity of that family. 



Bellerophon, Montfort, 1808. 



Syn. — Microceras, Hall. 



JXntr. — 150 sp. Cambrian to Carb. ; North America, Europe, 

 Australia, India. B. striatus, d'Arch. (Ixxxii, 95). 



Shell symmetrically convoluted, globular, or discoidal, strong, 

 few-whorled ; whorls often sculptured ; dorsally keeled ; aperture 

 sinuated and deeply notched on the dorsal side. 



Microceras, Hall, appears to be founded on the embryonic 

 volutions of a Bellerophon. 



WARTHiA, Waagen, 1880. Smooth, globular, not umbilicated, 

 without slit-band, and having a tolerably deep rounded sinuosity 

 on the outer lip ; inner lip only very slightl}'- callous. Fossil. 

 Salt Range, India. B. brevisinuata, Waagen (Ixxxii, 96, 97). 



MOGULiA, Waagen, 1880. Globular, without well-developed 

 slit-band ; mouth oval, outer lip with a shallow angular emargi- 

 nation, inner lip callous ; no spiral sculpture. B. regularis^ 

 Waagen (Ixxxii, 98, 99). Carboniferous; India. Possibly = 

 Warthia. 



PATELLOSTiUM, Waagen, 1880. Mouth very much expanded 

 and the lips spread out patella-like, the inner lip not being cut 

 out where it touches the preceding volution. Bell, macrostoma, 

 Proem. Bell, megalostoma, Eichw. 



WAAGENiA, L. G. de Koninck, 1882. Shell subgiobular, usually 

 a little higher than wide, and slightly compressed on the sides ; 

 whorls completely embracing, leaving no trace of umbilical 

 opening, that region being covered with a callus which appears 

 to have been deposited by a special organ, of which the related 

 genera are deprived ; slit-band narrow, a little inflated ; surface 

 covered with small imbricated plications or tine lines of growth, 

 and showing a pattern of coloring. Distinguished from Bellero- 

 phon by the umbilical callus. Distr. — 3 sp. Carboniferous ; 

 Europe. W. Ferussaci, d'Orb. 



