452 FOSSILS OF THE HUDSON RIVER GROUP. 



exceedingly common and very well preserved in our neighbourhood, 

 Orthis Occident alls (Hall) is abundant here and at the H umber River. 

 Orthis (^ formerly Spiri/er) lynx (Eichwald). I have obtained one or 

 two specimens of this fossil from Humber Bay. 



Among the Conchifera we have in the Aviculidce : Avicula 

 demissa (Conrad), an abundant fossil ; and Amhonychia radiata 

 (Hall), is also excessively common. In the Mytilidcs we have the well 

 known Modiolopsis modiolaris (Conrad), a very plain looking shell 

 notwithstanding its long name. Modiolopsis curta (Conrad), is rather 

 rare. Besides these two species, M. anodontoides, and M. /aba, with 

 Ortkonota parallela (Hall), have also been obtained from the shale 

 at Weston. 



Nneula postriata (Conrad), is an example from the family of the 

 Arcades. 



In the Trigonidoe Lyrodesma plana (Conrad), with its peculiar 

 radiating teeth has been discovered. I have also obtained Gleido- 

 phorus pilctnidatus (Conrad), (family of the Cyprinidce) from the 

 fine green shales of Weston, and Prof. Chapman has the same species 

 from Toronto ; but it does not appear to be common. 



Chcetetes lycoperdon (Say), is the most common and at the same 

 time the only coral yet discovered here. It occurs both in the " puff- 

 ball " and branched forms at all the localities. 



We have as yet no Cystidece, and only the stems of Cinnoidece, 

 principally Glyptocrinus decadactylus (Hall). 



ximong the mysterious Graptolites we have G. pristis (Hisinger). 

 I have lately obtained several very good specimens. G. Bicornis also 

 occurs in the Humber Valley, but the forked ends are generally 

 broken off. 



The fossils mentioned in the above list comprise merely the charac- 

 teristic forms of the Hudson River Group, as obtained in my own ex- 

 plorations around Toronto. A few other forms occur, but not in 

 sufficient abundance to be considered characteristic ; and I have there- 

 fore abstained from alluding to them. I trust, however, that this 

 brief notice may induce some of the younger members of the Canadian 

 Institute to turn their attention to this interesting study, and that our 

 list of fossil species may in this manner be eventually much increased. 

 I think it but right to add, that m.j own attention was directed in the 

 first instance to this pursuit, by a paper on Trilobites which appeared 

 in a recent volume of our Journal. 



