29O NEW YORK STATE MUSEUM 



that species H. b 1 a i n v i 1 1 i i differs in its much more rapidly 

 branching zoarium and consequent shorter cells, producing a fuller 

 and denser stock. 



Middle Devonic. Gaspe Basin, P. Q. 



CORALS 



Pleurodictyum lenticulare Hall var. laurentinum nov. 



Pleurodictyum lenticulare is a species of the Helder- 

 rjergian (New Scotland) fauna characterized by its very large and 

 few cells, the walls of which are strongly marked by nodose and 

 "broken septa. A central cell, hexagonal in form, is bounded by 

 six others and it often happens that the development of this spe- 



M 



4H$ 



Pleurodictyum lenticulare var. laurentinum 



cies does not pass this primitive expression. The form before us 

 lias the same form and size of cells which are marked by radial 

 nodose and denticulated septa, these being most prominent and 

 most irregular at the base. The lenticular corallum however grows 

 to larger size, showing three cycles of cells about that which may 

 be taken as central. In the measurements of the cells the New 

 York and the Gaspe forms are alike. 



Lower Devonic. Grande Greve and Perce rock, P. O. 



GRAPTOLITES 

 Chaunograptus gracilis nov. 



A shell of Leptostrophia magnifica Hall has affixed 

 to it an irregularly branching black conchiolinous repent fossil which 

 in structure and substance seems to be congeneric with the peculiar 

 organism described and figured by Hall as Dendrograptus 

 (Chaunograptus) no veil us from the Waldron ( Niag- 

 aran) fauna [Geol. Sur. Ind. nth Rep't. 1881. p. 225. pi. 1, fig. 1, 

 2; before in Alb. Inst. Trans. 1879. v - IO > abstract, p. 2]. A com- 



