96 NEW YORK STATE MUSEUM 



of any definite facts as to the exact location and range of the 

 Trenton fossils in the various outcrops within the state. 



Of the fossils enumerated, those entering the Trenton or be- 

 ginning in the Trenton would be available for an analysis; of 

 these, however, Leptaena r h o m >b o i d a 1 i s , L o p h o s - 

 pira bicincta, Liospira americana, Pterygo- 

 metopus c a 1 1 i c e p h a 1 u s, S t o m a t o p o r a i n f 1 a t a , 

 Whitella ventricosa, Protowarthia cancellata, 

 Isotelus maxinaus, Illaenus americanus, Con- 

 rad e 1 1 a c o m p r e s s a , C a 1 y m m e n e s e n a r i a , B y t h o - 

 cypris cylindrica are found to occur in one or another 

 locality of the lower, middle or upper Trenton, and are thus 

 unable to give the desired clue. Of the remaining species, 

 S t r e p t e 1 a s m a corniculum is reported by Hall to occur 

 principally in the lower Trenton, Orthis trie en aria in the 

 lower Trenton in New York, while in Minnesota it is also found 

 in the middle third of the Trenton ; Callopora multitabu- 

 1 a t a is in Minnesota positively known from the lower Trenton 

 and doubtfully from the middle Trenton, P h o 1 i d o p s t r e n - 

 tonensis is of uncertain position at Middleville, a small 

 variety of the same species is however in the west restricted to 

 the lower Trenton, O a r i n a r o p s i s carinata probably is 

 restricted to the lower and middle Trenton of New York; and 

 Zitteloceras hallianum is a Black river fossil in the 

 west and was known to Hall only from the lower Trenton at 

 Middleville. 



Bronteus lunatus was described by Billings from the 

 Trenton of Ottawa; according to the Geology of Canada (p. 177) 

 it is associated there with a most remarkable fauna of crinoids 

 and asteroids, only about 150 feet below the base of the Utica 

 beds, while in the same work (p. 173) it is also reported from 

 Murray bay together with such lower Trenton forms as Orthis 

 tricenaria, Din orthis pectinella, in a section giv- 

 ing 200 feet of limestone above the Black river beds. It appears, 

 hence, to occur in the lower and upper third of the Trenton, 

 while Clarke reports it also from the middle third of the 



