80 NEW YORK STATE MUSEUM 



kill shale is now considered as being as old as the Chazy formation. 

 We have also found a specimen in the Indian Ladder beds. This 

 species ranges therefore in the shales of Eastern New York from the 

 Chazy formation to the top of the Lower Siluric. 



Diplograptus (Mesograptus) putillus Hall 



Hall originally described as Graptolithus putillus in 

 the Canadian Organic Remains, decade 2, a small graptolite from 

 the " Hudson River group " of Iowa, that afterward was found to 

 range through the Eden beds of Ohio (title 49, page 68) and to 

 occur in many localities in the Utica shale of New York (title 60, 

 page 416). Our subsequent work has shown that this minute type 

 ranges in several mutations which are especially characterized by 

 different size, from the Normanskill shale through the Snake Hill 

 beds, the Canajoharie shale into the Utica shale. One of these 

 (from the Normanskill shale) has been distinguished before as 

 Climacograptus putillus mut. eximius (op. cit. 

 page 420). Also the mutation of the true Utica horizon is dis- 

 tinguished by extremely small size, while those of the Canajoharie 

 and especially the Snake Hill beds are remarkable for their greater 

 size. It must be these larger mutations which characterize in 

 Sweden a zone below that of Diplograptus quadrimu- 

 cronatus. 



The species has been currently referred to Diplograptus, while the 

 present writer placed it in the Graptolites of New York with 

 Climacograptus on account of the frequent Climacograptus aspect 

 of the rhabdosomes. Part 6 of the " British graptolites " by Lap- 

 worth, Elles and Wood (title 58, page 256), proposes the subgenus 

 Mesograptus for " forms in which the appearances presented are in 

 part those characteristic of a typical Diplograptus (Orthograptus) 

 and in part those more characteristic of a typical Climacograptus." 

 It would seem that the subgenus Glyptograptus also contains forms 

 quite similar to our species. 



Diplograptus (Mesograptus) mohawkensis nov. 



PI. 2, figs. 18, 19 



Diplograptus foliaceus (in part) auctorum. 



Rhabdosome small, about 15-22 mm in length and 1.5-2 mm in 

 width; the latter rapidly attained (in about 3 mm), in the largest 

 specimen again narrowing in antisicular direction. The sicula has 



