430 Fossils of the Chazy Limcstoiie. 



Locality and formation. — Abundant in Chazy limestone in the 

 neighbourhood of Montreal, and more rarely at the Mino-an 

 Islands. 



Cystide^e. 1 Species. 



The following species of Cystidece from this formation were 

 described in Canadian Fossils, decade 3. Glyptocystites For- 

 besi ; Malocystites Murchisoni ; M.Barrandei; Palceocystites 

 tenuiradiatus ; P. Dawsoni ; and P. Chapmani. 



Among the fossils collected at the Mingan Islands during the 

 present year 1859, there are a few detached plates closely resem- 

 bling those of P. tenuiradiatus, and others similar to those of 

 G.Forbesi, but they are obscurely preserved, and better specimens 

 must be procured before the species can be determined. Associ- 

 ated with these there is a single plate of a new species of Pala?o- 

 cystites, which I propose to describe as follows : 



Pal.eocystites pclcher. (N. s.) 



Description. — The only plate that I have seen is pentagonal 

 and in form somewhat like a low five-sided pyramid. The sloping 

 faces are striated by deep narrow sulci at right angles to the edge 

 of the plate as in P. tenuiradiatus. The five sloping angular 

 edges which radiate from the centre to the angles of the plate 

 have each a single deep sulcus and this character is the only one 

 by which this species can be distinguished in detached plates 

 The sloping angles in P. tenuiradiatus are in all the specimens I 

 have seen, solid, and exhibit no trace of a furrow. In this speci- 

 men, although the form is that of a low pyramid, yet the apex 

 is truncated, with a small concave space in the centre around 

 which the upper ends of the sloping angles form five small eleva- 

 tions. The sloping faces are also a little concave, but these 

 characters may be the effect of weathering. Length of the sides 

 of the plate, about three lines, with from fourteen to sixteen sulci 

 to each face. It is most probable that in ihe perfect plates, all 

 the sulci are covered over as they are in P. tenuiradiatus. 



Locality and formation. — Mingan Islands. Chazy limestone. 



Collectors. — Sir W. E. Lo^an. J. Richardson. 



Crixoide^e. 14 species. 



Of the Chazy Crinoids, the following are described in Decade 

 4: Blastoidocrinus carchariadens ; Pachyocrinus crassibasalis ; 

 Hybocrinus pristinus ; Palwocrinus striatus ; and Rhodocrinus 

 asperatus. Besides these the columns of nine other distinct 

 species are known to me in this formation. 



