GRAPTOLITES OF NEW YORK, PART 2 22 1 



appears to have been very solid. Its surface is smooth and fails to show 

 traces of growth lines. The branches which are given off monopodially 

 have a thickness that is a little greater than that of tenuiramosus 

 and are seen in one specimen to contract and expand regularly about eight 

 times in 10 mm from 2 mm to 2.5 mm, producing an apparent jointed 

 structure [see tig. 117, ii8|. Whether these segments correspond to thecae 

 or to the internodes between the bases of branches of the third order which 

 are all broken off, is not distinctly shown by the material in hand but the 

 fact of the abrupt, breaklike ending and that of the other specimen possess- 

 ing narrower uniformly thick (.2 mm) branches point to the latter view as the 

 correct one. In that case the branches of a higher order are here arranged 

 a little closer than in M . tenuiramosus, but otherwise the two species 

 are so similar that larger collections with more complete rhabdosomes — 

 for all we have at present are obviously but fragments — may prove their 

 specific identity. 



Mastigograptus arundinaceus ( Hall) 



Plate 12, figure 6 



Graptolithus arundinaceus Hall. Pal. N. Y. 1847. vol. 1, pi. 74, fig. 8, 8a 

 Dicranograptus arundinaceus Hall. N. Y. State Cab. Nat. Hist. 20th Rep't. 



1868. p. 227 

 Dendrograptus arundinaceus Gurley. Jour. Geol. 1896. 4:84 



This species is based on a single fragment, which was figured by Hall, 

 but not mentioned in either text or index and hence has 

 been overlooked entirely by cataloguers. Gurley was then 

 the first to publish a note on the specimen, stating that 

 " Hall's figure gives as much information as would a descrip- 

 tion of the same specimen, which, of course, is a mere frag- 

 ment " and adding, " I was able, however, to make out 

 the distinction from it of the Dendrograpti subsequently 



nublidiprl " f!r - " 9 Masti F°" 



pilUllbllCU. graptus arundin- 



T1 . . r 1 1 r 11 • 1 •• ace us (Hall). Copies 



In his manuscript we find the following description : of original figures 



The type specimen shows little that can not be inferred from Hall's 

 figure. The substance is a very thin film. Along the median line of both 



