298 THE CARBONIFEROUS SYSTEM. 



"P. cora, De Koninck, 'Mon. du Genre Productus,' pi. 4, fig. 1, 1847. 



" P. pileiformis, M'Chesney, ' Descr. of New Species of Fossils from 

 the Palaeozoic Rocks of the Western States of America/ p. 40, 1849. 



"P. Lyelli, Dawson, 'Acadian Geology,' p. 219, fig. 9, 1855. 



" P. Cora, Dav., < Mon. Carb. Brack,' pi. 36. fig. 4, pi. 42, fig. 9, 1861. 



" After a very careful examination of nine or ten specimens of P. 

 Lyelli from the Lower Carboniferous limestone of Nova Scotia, I 

 have reluctantly been obliged to place M. de Verneuil's species among 

 the synonymes of P. cora, the latter name (as may be seen by the list 

 of synonynies above given) claiming three years' priority. All the 

 Nova-Scotian specimens I have been able to examine were small, not 

 exceeding about 11 lines in length by some 12 or 13 in width. But 

 it must be remembered that, as a general rule, the Nova-Scotian 

 species and specimens, although adult, are small, and in this respect 

 are exactly similar to those we find in Scotland. The surface is 

 covered with numerous longitudinal, straight, or slightly flexuous, 

 narrow, thread-like, rounded stria?, with sulci, or interspaces, of rather 

 less width ; smaller stria? are also here and there intercalated between 

 the larger ones. The ribs are also regularly and closely crossed by 

 small concentric lines. 



"P. cora is a widely spread Carboniferous species, having been 

 found in many parts of America, India, Europe, etc. 



" Sir C. Lyell found this shell at Windsor, Horton Bluff, Shubena- 

 cadie, Gay's River, Minudie, and Cape Breton, in Nova Scotia. Dr 

 Dawson states that it occurs almost everywhere — at Pugwash, on the 

 eastern coast of Cumberland, at Lennox Passage, M'Kenzie's Mill, at 

 the eastern extremity of Wallace Harbour, etc." 



Mr Hartt has kindly furnished the following descriptions and 

 specimens of additional species of Brachiopoda : — 



Rhynchonella Ida, Hartt, Bed A, Windsor. Coll. C. F. Hartt. — 

 Shell elliptical, transverse, wider than long, rounded on the sides, 

 truncate in front, angular at the umbo, inequivalve. Dorsal valve 

 large, more inflected than the ventral, moderately arched, slightly 

 depressed in umbonal region, with a wide, slightly elevated mesial fold. 



Ventral valve less arched than dorsal, highest in the middle, from 

 which point it curves regularly to the umbo and posterior margin. 

 Umbo sharp, angle made by sides of valve at the umbo a right angle. 

 Outline of valve a right angled triangle rounded at the acute angle. 

 Sides of valve depressed. A shallow sinus corresponds to the fold of 

 the dorsal valve. It originates near the middle of the valve. Umbo 

 more or less strongly recurved. Foramen small, triangular. Deltidium 



