Section IV., 1892. [ 95 ] TRA^-s, Eoy. Soc. Canada. 



VII. — Illustrations of the Faatui of the St. John Group, No. VII.^ 



By G. F. Matthew, M.A. 



(Read 31st May, 1892.) 



This paper contains descriptions of the fauna of the Arenig horizon (Div. Sd) in the 

 Bretonian Division and also of certain graptolites and brachiopods of Bands a and b of the 

 same Division. The species are arranged according to their zoological standing, and not 

 their stratigraphical position, though the great majority are from Band d (Arenig horizon) 

 of the Bretonian. 



PEOTOSPONGIA (?) Salter. 



Calcareovis nodules from the Arenig horizon not infrequently show fragments of 

 the net of a Lyssakine sponge. These consist of cruciform spicules of two orders of size 

 but as the network is more or less broken and does not show the outline of the sponge 

 the material is not sufficient for specific or even generic determination. 



Horizon and Locality. Black carbonaceous shales of Div. Sd at the Suspension Bridge, 

 St. John. 



HYI>ROZOA. 



The graptolites first collected from the shales of the Bretonian Division were, with 

 the concurrence of the Director of the Canadian Geological Survey, Dr. A. R. C. Selwyn, 

 submitted to Dr. H. M. Ami, the assistant palaeontologist, who kindly examined them and 

 reported the result to me. Under the several species I have inserted his comments on the 

 specimens sent to him. 



It may be well to premise that the material on which these determinations have 

 been made is A^ery fragmentary and the hydrothecœ have been pressed very flat in the 

 shale, and often are somewhat distorted ; hence there is in some instances, considerable 

 difficulty in recognizing specific characters. 



BRYOGEAPTUS, Laptvorth. 

 Bbyograptus patens, n. sp. (PL VII., fig. 1 a — d.) 



Nat. Hist. Soc. of N. B., Bulletin x., p. vi. 



Primary branches of the hydrosoma spreading, at first dichotomous, then more irregu- 

 larly branching. There are about 10 hydrothecœ in the space of a centimetre, and the 



' It had been the intention of the writer to close this series of papers with the present article, but discoveries of 

 additional species in the St. John Grou[) during the past year has made it desirable to add another article to the 

 series to contain the descriptions of these new forms and the index to the whole series, as well ivsa table of species 

 showing the horizons at which they are found. 



