FOURTH, OB < ORONK EB \N BRAN< II 

 Arnioceras ceras, I \ 



I'Ul. Ill 



-1/ Bull M 

 Amm I. 11). 



Amm Ibid . pi \ 



Amm. ■ no*, II m i 



Semur, Whitby, I.. R 



Tli approximates to tin- aspect of Coroniceras, and also imil 



doselj the genera] form and characteristics of some varieties ol l / 

 Both in England and Germany, when the interior <>f the umbilicus or the Bmooth 

 compressed younger whorls are not preserved, even tin- most acute observers are 

 apt to consider the ad nil whorl a< belonging to Turneri, Sunn' of Quenstedt's 

 - Plate XIII.. may be either ceras or Borne allied b] 

 1 In- keel is prominent, the channels are broader and deeper than 

 usual, the geniculsB are prominent and Blight! y benl forward, the Bides, however, 

 Bat and slightly convergent, and the piles Btraight and smooth, as usual in tliis 

 Tin- piln begin upon the third quarter of the fourth whorl. 

 The superior lateral lobes are Bomewhal longer than the abdominal lobe. The 

 inferior lateral saddles are one fourth deeper than the superior lateral-, the infe- 

 rior lateral lobes one half shorter than the Buperior laterals on the latter half of 



the Birth volution. 



A specimen in the Museum of Stuttgardt, locality uncertain, is referred t<> the 



Geometricus cone. Tun young specimens from the Bucklandi zone, labelled 



N _7 Q ■ - collection, also probably belong to tln> 



species, The young are Bmooth, and the form differs from that of typical 



only in being a trifle stouter. The channels, perhaps, also appear at quite 



I, Imt this sometimes occurs in specimens of the typical form. 



There is also a large specimen from Jettenburg. 



What appeared to be very close allies of this Bpecies were collected l>\ Pro- 

 ii at [pishguaniina, in Northern Peru. 1 



Arnioceras Bodlcyi, Hyatt 



I I . I . -..I II Ml I 



Am 

 Amm 



II 



There are t h r.-. ■ varieties in this figured on Plate II 



it, thick whorls; the second ied \vlmii 



the third, i I Plate II Pig 24, has flattened whorls like those 



of the second variety, but thej >\liat wider on the - 



