L'-Jll IHI'TYCIHM KKAS, Coclll.ot KU AS. KIT. 



(JeBua PTYCHOCERAS, .Khl.. 



Shell bent once upon itself; the two s* raight port ions in contact . 



Kight species. N'eocomian to ( 'ret aceous. l^tirufn' ; India ; 

 United Stale*. 

 I*. KMKIUCIA.MS, d'Orb. 1*1. lol. fig. ."):><;. France, 



Subgrnus Diptychoceras, (<-.\\>\>. 



Three straight limbs in contact. A Ptijclutrrrti* in every 

 respect except that it has an additional limb which incurves, en- 

 veloping both the preceding to a slight degree only. Meek con- 

 siders it doubtfully identical with /V//r//or,-/7/.v. 



Genus COCHLOCEKAS, H:un;r. 



Shell spirally elongated, scalarilorni. strongly sculptured: 

 sutures of septa with several rounded lobes. 



Three species. Alpine Triassic. Hullxl.nU. Aiixtriti. 



r. FISCHHKII. Hauer. PI. l(Ml. tigs. f>ls. .">P.). 

 Genus ANCYLOCERAS, .I'Ori,. 



Shell at first spiral, discoidal with scparate<l whorls; after- 

 wards produced a! a tangent and then bent back again upon 

 itself like a hook. 



Forty species. Infer. Oolitic, Cretaceous. ttnri>/tc: 

 America; United States. 



A. SPINKIERUM, Sowb. PI. 1(1(1, iig. 5 % 2l). (Jault. /< J ol/,-v 

 Genua ANISOCERAS, Finer. 



Shell at first spiral, helicoid. whorls separated, at length more 

 Or 1688 prolonged and reflected; transversely ribbed: sutures of 

 septa with live lobes and saddles, all bipartite. 



Twelve species, (iault to Upper ( ireensand. />/"/><. ( 1 reta- 

 ccoiis. .Jui'assic, India. 

 A. SAUSSUREANUS, Pictet. IM. loo. tig. 528. 



G.-imj. SCAPHITES, Parkinson. 



Shell at first: closely spiral, involute, at length detached and 

 recurved; sn'.nres many lobed. lobes foliated. 



Nineteen species. Oolitic, Cretaceous. Kurnftt-; Imlin; 

 I'nlh'd Sfd-fi'x. 



S. K(.)i AUS. Sowb. PI. KlO. Iig. .VJ7. Chalk marl. S//s.<r./-, ]-]n<j. 



