GUAPTOLITES OF NEW YORK, PART 1 673 



corresponding to the Tetragraptus beds of the Deep kill, in the Middle Arenig 

 of St David's, in the Lleyn peninsula of Wales and in Shropshire. In Scandi- 

 navia the species does not appear to have as yet been clearly recognized ; 

 Herrmann \loc. cit.] cites it as "doubtfully in Phyllograptus shales, Norway." 

 Barrois describes D. n i t i d u s as common in the graptolite schists at 

 Boutoury near Cabrieres ; and the younger Etheridge I'ecords it from Castle- 

 maine in Victoria, Australia, but his 

 identification is doubted by LapAvorth, 

 Elles and Wood. ,:.•„> t. , . . , 



FiK. 69 D 1 cl y m o jr r a p t u s n 1 1 1 d ii s Hall up. 



T> „„7,, TV,« ,^«;w,-,,.,r A^,c^^ ',c Krairment of branch, showing different aspects of 



Jienia?'KS. ine primary aiSk is thec.e due to different direction of compression. 



'■ •' Deep kill. x5.2.i 



observable in a considerable number of 



specimens. It is found close to the ape.x: of the sicula, so that the latter 

 appears to have been as a nde attached by only a very short nema and even 

 without the intercalation of such, as in figure 3. I have not observed any 

 disks on larger rhabdosomes, but this is possibly due to the fact that I did not 

 find any larger specimens so isolated and unencumbered by other fossils on 

 smooth surface.s that I was able to distinguish these delicate appendages. 



This species approaches D. p at u 1 u s on one hand, and D. e x t e n s u s 

 on the other, and it is difficult to assign some forms to one of the three. This 

 is specially true in regard to the differentiation of the closely allied species D. 



n i t i d u 8 and D. p a t u 1 u s. The closer arrange- 

 ment of the tliecae in D. n i t i d u s and the 

 greater width ol: the branches of D. patulus 

 tid'Ss Hall «p.V?aKment''oj branch' are tlic principal distinctive characters. The 



The periderm is lost and the form of 



thlp^i"tnrtolf'''Dli''pkili!'°xT''^' greater number of thecae within a certain space 



and the more rapid widening of the l>ranches will 

 also distinguish the typical D. n i t i d u s from D. e x t e n s u s. 



A few of the specimens which we had to refer to this species [fig. 5] 

 greatly surpass in length and width of the branches attained the examples 

 described from Canada and Great Britain. At the same time they show just 

 a little looser arrangement (11 in 10mm) than the typical D. nitidus, 

 but still a greater number of thecae in a unit than D. e x t e n s u s and D. 



