40 Bulletin 6 40 



Orthoceras demus Hall. 



Specimens referred to this genus were found in the Ithaca 

 group at station i-ii. 



Orthoceras leander Hall. 

 From the Ithaca group. 



Orthoceras pertextuin Hall. 



This species is recorded from the Ithaca group by Hall. 



Orthoceras bebryx var. cayuga Hall. 



This is the most abundant species of Orthoceras found at Ith- 

 aca. It ranges throughout the Ithaca group. 



Gomphoceras tumidufn Hall. 



This species is rather common in the Ithaca group. A small 

 variety of it occurs in the upper Sp. Icevis zone of the Portage. 



Porcellia nais Hall.* 



This is a rare species occurring occasionally in the Ithaca group. 



Goniatites sinuosus Hall. 



This species ranges from the lower Portage through the Ithaca 

 group. 



Goniatites peracutus Hall. 



A single well preserved specimen from station 4-2, about fif- 

 teen feet above the Spirifer Irsvis zone. (Omitted in list, p. 23). 



Goniatites complanatus Hall. 



This is a common species in the Portage. 



Goniatites discoideus Hall. 

 Common in the Portage. 



Goniatites simulator Hall. 

 Ithaca group. — Hall. 



Goniatites uniangularis Con. 



Some specimens from the Ithaca group are doubtfully referred 

 to this species. 



Pelecypoda. 



Phthonia cylindrica Hall. 



A single entire specimen of this species has been found at 

 * Classed by the writer among cephalopods, doubtless by mistake. — Ed. 



