396 THE CANADIAN NATURALIST. [Vol. X. 



NOTE OX THE OCCURRENCE OF SIPHONOTRETA 

 SCOTTCA, DAVIDSON, TN THE TJTICA FORMA- 

 TION, NEAR OTTAWA, ONTARIO. 



By J. F. WniTEAVKs. F.G.S. 

 (Read before Aiuerie;in Association for Advancement of Science, Montreal, 1882) 



In the spring of 1881, three specimens of a remarkable spinose 

 hrachiojwd were collected by Mr. J. W. H. Watts, R.C.A., from 

 a baud of impure limestone in |the Utica slate, at Cumming's 

 Bridge, near Ottawa. These specimens, which Mr. Watts has 

 ^ince presented to the Museum of the Geological Survey of 

 Canada, consist of two perfect examples of the beaked and per- 

 forated valve, which is probably the ventral, and of one detached 

 dorsal valve in which the beak is obsolete. Over most of the 

 central area of the sides of the valves the spines are broken off, 

 and where this is the case the surface is marked with pitted im- 

 bricating concentric lamellag — the pits representing the fractured 

 bases of the spines. In each case the margins of the valves are 

 ^iensely fringed with a single and continuous row of fine hair- 

 like spines, except immediately upon the beaks. 



Upon examination with an ordinary simple lens it was at once 

 apparent that these specimens are referable to De Vernueil's 

 genus Siphonotreta, and that in most respects they bear a very 

 close resemblance to an English species, the S. Anglica of Prof. 

 Morris. But the spines of S. Anglica are distinctly stated to 

 be annulated, whereas those of the Canadian specimens appeared 

 perfectly smooth when viewed under an achromatic microscope 

 with an inch and a half objective. 



A few month ago the writer had occasion to send come Cana- 

 dian fossil Bracliiopoda to Mr. Thomas Davidson, F.R.S., for 

 examination and comparison with British species. In the parcel 

 forwarded the three examples of the Siplionoti'eta from Cum- 

 mino's Bridge were included, and in a letter received from Mr. 

 Davidson in May last, they are reported upon as follows: — 



" The Siplionotreta from near Ottawa interests me much. It 

 is identical in shape and characters with the Upper Llandeilo 

 species, which I named Siplionotreta Scotica. I am very un- 

 <3ertain whether the Wenlock Shale species, named S. Anglica, 

 by Morris, is the same or not. Only one crushed specimen of 

 the S. Anglica has been found, and its spines are annulated, as 

 <iescribed by Morris. I could see no annulations in the spines 

 of the many specimens of S. Scotica, found by Mrs. Gray in the 



