AMMONITID^. Yl 



COROCERAS, Hyatt, 18*77. The species all have numerous lobes 

 and saddles, with smooth sutures, and a large exterior lobe which 

 is A'ery broad and prominent ; they are plicately ribbed and ver}^ 

 involute, the umbilicus nearly covered ; mouth more or less 

 hooded or constricted. G. ellipticus, Hauer (^xxxvii, 8, 9). 



Choristoceras, Hauer, 1815. 



Disfr. — 9 sp. Trias. G. Mar^hi, Hauer. 



Shell discoidal ; bod^^-chamber short ; ribs interrupted b^^ the 

 convexity of the inner whorls, bat continuous on the outer. 



HELICTITES, Mojs., 18t9. Whorls with strong, uninterrupted 

 ribs; lobular line undulated, with small, almost microscopic 

 denticulations. G. geniculatus, Hauer. 



BADIOLITES, Mojs., 1879. Couvcxit}^ of the whorls narrow and 

 carinated ; ribs falciform ; lobes not truncate, undulated, except 

 the antisiphonal lobe, which is long and pointed. G. er?/x,Munster. 



R.HABDOCERAS, Haucr, 1860. 



Distr. — B. Suessii, Hauer. Alpine Triassic ; Germany (xxxii, 

 20, 21). 



Shell straight, orthoceratoid, strongly sculptured; septa with 

 rounded lobes. 



Rod-like, elongated forms with oblique annular sculpture and 

 simple curved lobes ; still very imperfectly known. 



CocHLOOERAS, Hauer, 1860. 



Utym. — Gochlos, a snail-shell, ceras, a horn. 



Distr. — 3 sp. Alpine Triassic ; Hallstadt, Austria. G. Fisch- 

 erii, Hauer (xxxii, 25, 26). 



Shell spirally elongated, scalariform, strongly sculptured; 

 sutures of septa with several simple rounded lobes. 



The whorls are spirally coiled to the left, with continuous ribs 

 and simple curved lobes. 



Pinacocerse. 



Body-chamber short, half or three-quarters of the last whorl ; 

 shell flattened, discoidal ; sutural line very complex, with three 

 groups of lobes , adventive, principal and auxiliary). 



PiNACOCERAS, Mojs., 1873. 



Syn. — Megaphyllites and Carnites, Mojs., 1878. 



Distr. — 12 sp. from the Triassic. P. Metternichii^ Hauer, 

 (xxxv, 71). 



Shell narrow, aperture high, smooth, seldom with knob-like 

 enlargements on the surface. Body-chamber one-half to two- 

 thirds of a whorl long ; aperture with short lobular process of 

 the convex portion. Attachment ring commencing a short dis- 

 tance from the aperture and extending to the posterior end of 



