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 of. gigas Dekay^ ■ (rr) 



Primitia (mmute 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 c/. 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. & R. (r) 



Eusarcus triangulatus C. & R. (c) 



E ? longiceps C. & R. (r) 



DoHchopterus frankfortensis C. & R. (r) 



D. latifrons C. & 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.'* 



