FOURTH, OB I ORONK BRAH BRAXl !I 17.' 



sutures <>f tin- Dearly adult kridion are, however, often quite distinct from th< 



: the same rise, but whether this difference la invariable or not, 1 

 am unable to say. 



The largi len in the Museum of Stuttgardt is l~i> nun. in dian ■ 



( »n the latter part of the whorl the pilsa are nearly obsolescent, with no genicular, 

 1 1» ns i sactly to the condition of tho» I The 



rounded, channels very Bhallow, but the keel still prominent There 

 : \ nM specimen figured bj Quenstedt ' 

 II together with his Fig. '.', quoted above, bIiow that th«' living 



chambers of the nealogic Btagee probably exceeded one volution in length, but 

 we have not been abl I tin what thej were in adults. 



Coroniceras lyra, Htatt. 



II .1.- IT. h; 1 IT. I'l.i.. \. II C . I Ik -mini,. Fl Ml. I ic II 



Hyatt, B ill Mm I 



Amm • ,• .liir.i. pi. ri. I 



Amum. mullicufi:-. II u i Upen, pi. ri 



in'. Wriort, Lum Amm., pi in., iv. 



1. r. i Imund, Boll, rubii . 



\ LB. A 



l-l.t. I \ i . i | i --I i 



This is siniilai I ' The bases of the Buperior lateral saddles 



very narrow on tin- sixth or seventh whorl. The bases of the superior I 



iif proportionally broad, and <>n ih<' same line with the genicube, instead 

 of on th>' side, as in other varieties. The Buperior lateral Baddies are pointed, 

 but on the eighth whorl they become broader, and are subdivided by three mar- 

 ginal lobes The abdominal 1< »!»*• is longer than the Buperior laterals l>\ about 

 one thini. and the in il saddles exceed in depth the Buperior laterals by 



rth. 



B 



I'Ulr I V I 



This has young with the same rapid lateral increase and deep pit-like um- 

 bilicus during the first whorl which was previously observed in I 

 The lateral in< however, less marked on the second whorl, and the 



abdomen * ne more prominent and rounder. The pila 



folds, probably on the second or third quarter of this volution, and the an 



which is to become the keel, appeared on the lasl <\ this or the 



r of the third volution. The pila? never overhang, noi abdo» 



•h than the dorsum, as in the youn ' 

 ' I skipped entirely, and it is replaced I 



! the tnore :i<I\ 



men on the third whorl b the keel | 



