GRAPTOLITES OF NEW YORK, PART 2 



263 



thecae bear long apertural spines, which in some specimens are extremely 

 slender (176), in others relatively stout (177). The branches are first 

 broadly convex, then slightly concave, but mostly approach a straight line 

 and appear rather rigid when compared with those of the type of the species. 

 This feature they exhibit in a still stronger degree than the British repre- 

 sentatives of the variety spin if er, although they do not exceed them in 

 final width (1 mm). 



177 178 



Fig. 176-78 Leptograptus flaccid us var. spin if er niut, tre 11 ton en sis nov. Fig". 176, 

 177 Reverse views of the sicular end showing its spinose character. Fig. 178 Enlargement of 

 mature portion of branch, x 5 



While the British variety, as well as the typical species occur only in 

 the Hartfell shales, the New York representatives have been observed only 

 in the older Normanskill shale (Glenmont, N. Y.). It is mainly for this rea- 

 son that we emphasize the slight difference in relative rigidity of the branches. 



Leptograptus flaccidus (Hall) var. spinifer Elles & Wood mut. trifidus nov. 



A unique specimen [fig. 179] showing the characters of L. flac- 

 cidus var. spinifer was collected by the writer at Mt Moreno. It 

 possesses between the sicula and the branches a strong carbonaceous web. 

 The whole central portion is evidently much thickened, and from its lower 

 side three processes are suspended, two of which terminate bluntly, while 

 the middle one tapers to a point and may represent a hypertrophic virgella. 

 The processes are longitudinally wrinkled and do not seem to have been 

 composed of thecae. 



We see in this interesting variety a similar feature as is observed in 



