GRAPTOLITES OF NEW YORK, PART 1 - 651 



Position and localities. T. fruticosiis has, at the Deep kill, been 

 collected in graptolite beds 1 and 2. In both beds which belong to the 

 Tetragraptus zone, it occurs in much larger specimens than have been 

 hitherto recorded ; and with the forms found in bed 2 it reached distinctly 

 the acme of its development. In bed 3 (zone Avith Didymograptus 

 b i f i d u s and Phyllograptus anna) it is not found any longer 

 at the Deep kill in its typical development. Hall reported the form from 

 " the shales of the Quebec group at the upper end of Orleans island, and three 

 miles above river St Anne." Ami records it from three localities near Levis, 

 in two of which it is a member of the Didymograptus bifidus fauna, while in 

 the third it is one of the Tetragraptus fauna. Gurley lists it as occurring in 

 the " Main Point Levis zone " and the " Phyllograptus anna zone," which 

 I'ange tallies with that at the Deep kill and with Ami's results. Billings 

 identified graptolites from the division P at Cowhead, Newfoundland, with 

 this Quebec species. In Britain it is, according to Elles's reports and those of 

 the monographers, poorly represented, but occurs in the Arenig of south 

 Scotland and of the Lake district. In Sweden and Norway it is found in the 

 Phyllograptus shale (fide Tornquist, TuUberg and Brogger) ; in Australia, 

 McCoy has declared specimens from various outcrops of the Lower Siluric 

 slate in Victoria to be " perfectly identical in all respects with the North 

 American species." 



Remarhs. From the figures or descriptions furnished by the authors, 

 cited above, it can be concluded that they had either only immature 

 specimens or proximal parts, or small mutations before them. As our series 

 contains excellent, fully developed specimens and exhibits division into two 

 variations, we have been able to enlarge the original description considerably. 

 The difference in the character of the earlier and later thecae of the branches 

 has been pointed out before by the writer [1902, j).589], and its phylo- 

 genetic significance set forth \see also Introduction, p.5Sl]. 



In the Tetragraptus bed there occur two greatly differing variations of 

 the form, which however are sufiiciently connected by transitional forms 

 to warrant their I'etention within the bounds of one species. In one, the 



