GRAPTOLITES OF NEW YORK, PART 2 



439 



apparently extending the greater length of rhabdosome. Nemacaulus not 

 observed. 



Position and localities. This species has in this State thus far been 

 found only on the west bank of the Hudson river below the power house 

 at Mechanicville in association with Diplogr. foliaceus, Glos- 

 s o g r . q u a d r i m ucro n a t u s var. a p p r o x i m atus, Cor y n o i d e s 

 curt u s var. c o m m a and a great number of other fossils, 

 in black shales [see Bui. 42, p. 5 20] which are thought to lie 

 close to the base of the Utica shale. In Canada it is, accord- 

 ing to Gurley, only known from the Upper Dicellograptus 

 zone at Magog, though Ami has also referred a form from 

 the shale at Quebec to this species. In Great Britain C . 

 can d atus is cited by Lapworth as one of the character- 

 istic graptolites of the Dicranograptus clingani zone of the fJ 

 lower Hartfell beds and of the upper flags of the Ardwell 

 beds in the middle division of the Moffat terrane, of the 

 Trolodden beds of the Girvan district and the Aldress beds 

 (Lower Caradoc) of Wales and the west of England. Its 

 horizon is there above that of Coenograptus gracilis, and 

 hence corresponding to our upper Trenton zone. It also 

 occurs in Ireland and in Scandinavia. 



Remarks. The specimens from Mechanicville aeree in 

 form and dimensions of rhabdosome and the possession of 

 the long filiform virgella exactly with the original figures Fig. 4°e en mac 0. 



^ >i rapt us caudatus 



of C . can d a t u s given by Lapworth and the description \^Z\^i^ttl^t 



. ' 1 /— • 1 membrane of virgella. 



01 the Magog specimens by Gurley. x s 



Climacograptus antiquus Lapworth 



Plate 28, figures 2S, 23 



Climacograptus antiquus Lapworth. Geol. Mag. 1873. 10:134 (nom. 



nud.) 

 Climacograptus caelatus Lapworth. Cat. West. Scott. Foss. 1876. 



p. 6; pi. 1. fig. 56 



