96 NEW YORK STATE MUSEUM 



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

 Trenton fossils in the various outcrops within the st«'ite. 



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

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

 these, however, L e p t a e n a r h o m b a i d a 1 i s , L o p h o s - 

 pira bicincta, Liospira americana, Pterygo- 

 metopus callicephalus, Stomatopora inflata, 

 Whitella ventricosa, Protowarthia cancellata, 

 Isotelus niaximus, Illaenus americauus, Con- 

 radella conipressa,Calymmene senaria,Bytho- 

 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, 

 Streptelasma corniculum is reported by Hall to occur 

 principally in the lower Trenton, Orthis tricenaria in the 

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

 in the middle third of the Trenton ; Callopora multitabu- 

 lata is in Minnesota positively known from the lower Trenton 

 and doubtfully from the middle Tienton, Pholidops tren- 

 t on e n s i s is of uncertain position at Middleville, a small 

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

 the lower Trenton, Carina ropsis 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. 



Bronte us lunatus was described by Billings from the 

 Trenton of Ottawa; according to the Geology of C(inud<i (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 re]>orted from 

 Murray bay together with such lower Tivnton forms as Orthis 

 tricenaria, Dinorthis pectin ell a, 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 



