42 NEW YORK STATE MUSEUM 



Cyrtolites sp. (very young example) (rr) 



Trocholites ammonius Conrad (r) 



Cyrtoceras sp. nov. (r) 



Spyroceras bilineatum (Hall) (rr) 



Triarthrus becki (Green) (r) 



Isotelus cf. gigas Dekay 1 (rr) 



Primitia (minute form) (cc) 



Eurychilina (r) 

 Pterygotus prolificus Clarke & Ruedemann 

 P. nasutus Clarke & Ruedemann 



A much larger collection was obtained two miles farther south- 

 west in the bluestone quarries at the northeastern outskirts of 

 Schenectady, notably the Dettbarn quarry. This has afforded : 



Sphenophycus (Hall) (cc) 



Mastigograptus sp. nov. (r) 



Climacograptus typicalis Hall (cc) 



Lasiograptus eucharis (Hall) (c) 

 Crinoid joints 



Leptobolus insignis Hall (c) 



Lingula rectilateralis Emmons (r) 



Dalmanella testudinaria (Dalm.) (small) (c) 



Conularia trentonensis Hall var. multicosta nov. (r) 



Modiolopsis cf. modiolaris (Conrad) (c) 



Saffordia ulrichi nov. (rr) 



Cyrtoceras sp. nov. (c) 



Spyroceras cf. bilineatum (Hall) (r) 



Trocholites ammonius Conrad (small) (r) 



Triarthrus becki Green (c) 



Trinucleus concentricus Eaton (rr) 



Eurypterus pristinus C. & R. (r) 



E ? (Dolichopterus) stellatus C. 6- R. (r) 



Eusarcus triangulatus C. 6- R. (c) 



E ? longiceps C. & R. (r) 



Dolichopterus frankfortensis C. & R. (r) 



D. latifrons C. 6- R. (r) 



Hughmilleria magna C. & R. (cc) 



Pterygotus ? nasutus C. & R. (r) 



P. prolificus C. & R. (c) 



Stylonurus ? limbatus C. & R. (c) 



The next series of outcrops which, on account of the southwest 

 dip of the beds, are probably a little higher in the Schenectady 

 formation, are those at Rotterdam Junction. Prosser and Cumings 

 have described (title 33, page 658) a small section nine-tenths of a 



1 This is a large complete individual 6.5 inches long, from the " bluestone." 



