84 NEW YORK STATE MUSEUM 



it will be necessary to distinguish these Diplograpti more sharply if 

 they are to be of any use in the elaboration of the stratigraphy of 

 the shales. We therefore for the present restrict vespertinus 

 to the forms from the Canajoharie shale. Since Diplograptus 

 f o 1 i a c e u s Murchison, as since emended by Elles & Wood, 

 clearly represents a different type, we recognize D. vesper- 

 tinus as a distinct species. 



Climacograptus spiniferus Ruedemann 



We comprise under this name the form which in the Graptolites 

 of New York, part 2, page 411, had been described as C . ty p i - 

 c a 1 i s mut. s p i n i f e r from the shales at Ballston, Saratoga and 

 Bakers Falls (now Hudson Falls). This type is a common and 

 characteristic graptolite of the Canajoharie shale where C. t y p i - 

 calis is absent; it also occurs in the Snake Hill shale and enters 

 into the Schenectady beds. It is therefore in its range, as also in 

 its characters, so very distinct from C . t y p i c a 1 i s that it 

 should be recognized as a different species. I learn from Doctor 

 Ulrich that it also is a characteristic graptolite of a part of the 

 Martinsburg shale. The Mohawkian mutations of C . b i c o r n i s 

 (a Normanskill species) that have been cited by several authors, 

 the present included, probably all belong to spiniferus. 



Lasiograptus (Thysanograptus) eucharis (Hall) 



This minute form, which is remarkable for the frequent occur- 

 rence of entire colonies or synrhabdosomes, was originally described 

 by Hall as a Retiograptus, later, on account of the form of the 

 thecae, referred by the present writer to Diplograptus and in the 

 Graptolites of New York, part 2, page 397, brought with doubt 

 under Glossograptus. Last summer's investigation of the shales of 

 the Mohawk valley has afforded the writer a few specimens from 

 the Canajoharie shale of the Chuctenunda section and the Schenec- 

 tady shale of Schenectady, which at last establish the generic 

 position of this species. While those from the Chuctenunda reveal 

 the marginal lacework characteristic of Lasiograptus, the specimens 

 from Schenectady are partly pyritized and retain the fibrous thicken- 

 ings of the angles of the thecal walls (see text figure 24). 



