120 SUPPLEMENT TO THE 



After the preceding sheets were put in type, Mr. Glass was favoured by a large 

 parcel of fossils from Mr. George J. Hinde, Ph.D., E.G.S,, kindly sent at our request. 

 These fossils consisted of more than thirty species of spiral-bearing Brachiopoda from 

 North America, principally collected by Dr. Hinde himself. Of each species sent to Mr. 

 Glass there were a good number of specimens, in some cases more than a hundred. In 

 the most generous manner Mr. Hinde gave Mr. Glass permission to select out of these 

 fossils the specimens most suitable for his operations, and the result has been a number 

 of interesting discoveries including two new genera. 



In order to make more complete the history and characters of the spiral-bearing 

 genera, which Mr. Glass and myself have endeavoured to treat with some detail in this 

 Supplement, we have added descriptions and figures of the following preparations from 

 Dr. Hinde's specimens, either as directly representing species we possess in Britain, or as 

 reflecting light upon the proper classification of the spiral-bearing Brachiopods, a subject 

 which will be further considered in subsequent pages of this Supplement. 



Genus — Athtris, M'Coy, 1S44 = Spirigera, d'Orb. 



I have previously referred in this Supplement to Athyris sjnriferoides, an American 

 species, and have shown that its spirals and their attachments are similar to those in the 

 other species of Athyris, with the exception that in A. sjnriferoides the roof-shaped 

 projection in the loop is rather larger, and the hook-shaped attachments of the primary 

 lamellse to the hinge-plate are more curved and open. Dr. Hinde sent to Mr. Glass a 

 number of shells of a species of Athyris from Widder, Ontario. They are smaller than 

 A. spiriferoides, and exactly agree in shape with a type-specimen of A. vittata sent to 

 me by Mr. Whitfield, and they also agree with Prof. Hall's figures of this species in ' Pal. 

 New York,' vol. iv, pi. 46, figs. 1 — 4. Mr. Glass has worked out very clearly and 

 perfectly several of these Widder specimens, and they show a spiral arrangement of the 

 ordinary Athyris type, with the single exception that the hook-shaped attachments of the 

 primary lamellae to the hinge-plate are still more curved, open, and loop-like than in 

 A. spiriferoides, but not perfectly circular, as represented in Hall's figure of the 

 interior of A. vittata. The loop in the Widder specimens is exactly like that I have 

 figured in Athyris planosulcata^ and does not agree with the figure of the loop of A. vittata 

 as given by Hall. 



