1 "I !; Ml. m|; , URONK EH \N HK \N< II 



Wright's visit to lii- oollection. Quenstedt's huge Bpecimen, 700 mm. in diam- 



described 1 as baving 1 1 1 « * pilse obsolescent near the termina- 



of the last volution, and the kc«-l as showing but little above the almost 



te channels. This, therefore, is an extreme example <>t' senile degeneration 



in the clino . ■■. but it has not yet reached tin- nostoli 



Coroniceras Gimiendenso, Htatt. 



I'Ul. V I | 1 ' I : .'. VI I .> I ». II. \ II I , k - II 



.imm G iiiiii. Der Jorafor., Wiiil Jahreshf , XII p 



A mm B ■ (,. Zll i ■ \ • r-t Wart . pi. xxvii ■ 



1 1 [. N 



: 1 . '-' 



• . | i , 



The adults of ilii- Bpecies are readily distinguishable from Cor.lym 1>\ the 

 smaller rise <•(' the whorls, the characteristics of the Butures, the extreme narrow- 

 if the abdomen as compared with the dorsum, and the broad, shallow chan- 

 nels. The keel is more prominent also than in Cor, tyra, and the pitas end very 

 abruptly with genicular <>\ pseudo tubercles. This peculiarity is observable on 

 the latter part <>t" the sixth whorl, and the bending forward of the genicular, as 

 they ri-<- on the narrow abdomen, is hardly observable on the cast until after the 

 completion of the seventh wborL <>n 1 1 * « - eighth volution the genie utae become 

 rominent on the cast, and the depressed geniculaa and pilsa form a single 

 arch slightly interrupted by the tubercular aspect <>f the former. These charac- 

 iint altered when the shell is present, but have about the same ex- 

 iipon 1 1 1 * - cast The geniculaa on the seventh whorl, in one specimen 

 prominent, and their forward bend plainly observable, though 

 without tubercles 



The abdominal 1<'I»<- i- broad and deep P ■•■ \ Oie superior lateral 



saddles and lobes are nearly obsolete, the inferior lateral lobes and the first aux- 

 iliary saddles are but slightly developed. On this account the inferior 

 saddles, which are of about the usual size, acquire remarkable prominence, 

 ve already noticed, in variety I , a tendency towards the 



suppression <>t' the superior lateral saddles, and here it is actually carried out. 

 The marginal lobe* and Baddies "i the superior laterals, however, remain on one 

 specimen from Anrgau, but on one from Semur onlj the inner of the three sad- 

 i laracteristics are present in the adults of this 



. 1 consequently are not «1 m- t«» old 



pari of the eighth whorl the pilae lose their tub< 

 : ime almost obsolete, being reduced I con- 



• ona «>t 'I. ed arched pilm, which are most prominent at the um- 



bilical shoulders, The channels continui i\ well defined, though much 



shallo I channel i 



the tenth whorl. <>n the second quart* whorl tin 



