il. OR 0X1 N'OTICER \N BR \' 217 



. which formed tin 4 partition above the keel, and above this again .1 i 

 sion of finer layers; but these did doI lill up the interior of the keel completely. 

 A hollow portion or rone filled in the ■ | » i « -« 1 the outer 



half of tin' interior of the keel. M\ not tches m.ik<- do mention of an} 



dark layer in these Bpecimena 



Oxynoticeras Simpsoni, Hi 



oiin.ii. II Mil I ic II. 



» Amm Simps , i 



1 7 

 Amm pi. xxxiii. t 



Whitby. 



TL - - quite different in form, sutures, and the amount of involution. 



and it to hold it as < 1 i - 1 i m - 1 than to confuse it with oxynotum. 



It is admirably figured by Wright. The Bhell is considerably more tumid, the 

 whorl thicker and Btouter than in h, and this peculiarity is observable even 



in the young. The amount of involution i- greater, and consequently the um- 

 bilicus is smaller, than in that species. The raarj much 

 simpler, especially as regards the auxiliary lobes and Baddies than in 

 It is intermediate in all its chs - between oxynotum and Lymemte, and this 

 is an additional reason for separating it from the former. 



If wi it. either tin* bj i form transitional to it is found in the 



>!lc 



Oxynoticeras Lymense, Htatt. 



taa ii. mm i . 



Awtaltl i . pi xlvi. tic 1 -3; pi \ 



Am xl.. xliii. 



Amm. ■■!.■ ■■ II ■- 



Thii nvolute form ol tnotvm, which deser 



name on • losely related to that Bp< 



Oxynoticeras ntunisin ilo. n 



Amm nrt,: ■:• nui 

 An. : 



I <'oplin'_' " Q 



i the adult hi- .i hollow keel. This i- lost in old age, the whorl 

 / ' 



form of th. n the M 



; n outline, and confirm I 



form at th vth. Hi 



