CEPHALOPODA OF THE (JKETAGEODS MARLS. 269 



The fragment preserves only a single septum the details of which are 

 given, enlarged to twice natural size in the figure on the plate, this having 

 been the lower limit of the septate portion; the next higher septum being 

 at the upper end of the fragment. 



The species is peculiar in its rapidly ascending spire ; also in having 

 the volutions higher than wide, instead of circular, and also in the numerous 

 but very distinct vertical folds or ridges. The concave upper side of the 

 coil showing the partial imbedding of the preceding volution will also 

 serve to distinguish it from other described species of this country, they 

 generally presenting round volutions while these are quite angular at the 

 junction of any two. 



Formation and locality: From the Lower Grreen Marls, at Neversink 

 Hills, New Jersey. Collection at Rutgers College. 



Genus HETEROCERAS D'Orb. 



Heteroceras Conradi. 



Plate XLV, Fig. 9-14. 



Ammonceratites Conradi Morton: Jour. Acad. Nat. Sci., Phila., 1st ser., vol. 8, 

 p. 313, PI. X, Fig. 1 ; Descrip. New Sp. Organic Rem. Cret. United States, 

 1843, p. 8. 



Helicoceras Conradi (Mort. ) Gabb : Synopsis, p. 38 ; Meek, Check List, p. 35. 



Cirroceras Conradi (Mort.) Meek: Geol. Snrv. New Jersey, 1868, p. 730. 



A single whorl of a species of Heteroceras, imperfect at both ends, and 

 in all probability nearly if not quite the last whorl of the specimen, repre- 

 sents the above synonyma. As will be seen by Dr. Morton's original 

 description, he considered it as alfliost a perfect individual, as he says in 

 his remarks : "The terminal end is nearly complete and almost on a line with 

 what appears to have been the mouth of the shell, and the two approach 

 within a quarter of an inch of each other." It is very evident, however, 

 when the specimen is examined by the light of present information and 

 knowledge of these peculiar shells, that the specimen, which is only 

 an internal cast of the non-septate portion, it belongs to a sinistrally 

 coiled spiral shell, where the volutions have not been in contact one with 

 the other, as, if they were extended far enough, they would overlap, leav- 



