﻿lis 



BRITISH CARBONIFEROUS BRACHIOPODA. 



wide and shallow ; beak obtuse, not much produced or incurved. The surface of each 

 valve is ornamented with about twenty obtusely angular ribs, which are strongly arched on 

 the lateral portions of the shell. 



Length 12^, width 13, depth 13 lines (Sir R. Griffith's specimen). 



Obs. This species is stated by Professor M'Coy to be common in red arenaceous 

 limestone, underlying the main limestone of the country, at Cookstown, Tyrone, in Ireland ; 

 and the only specimen I have been able to examine is one so labelled by M'Coy, and 

 which forms part of Sir R. Griffith's collection. With such scanty material before me, 

 I cannot venture upon any observations relative to its variations in form, age, and cha- 

 racter ; but the species seem well distinguished from other Carboniferous Uhynchonellce or 

 Camarophorias, by its general appearance. In the ' Synopsis,' Professor M'Coy describes 

 the shell as an Alrypa, but at p. 444 of the work on the species of palaeozoic fossils in the 

 Cambridge Museum, the author states it to be a Camarophoria. 



" The mesial septum in the dorsal valve strong, and about half the length of the 

 flattened rostral portion ; the mesial septum in the ventral one is nearly as long, and 

 diverges to form a large wide chamber at the beak." 



Sir R. Griffith's specimen does not show the interior, but on the external surface of 

 each valve a single median line may be perceived, extending from the extremity of the 

 beak and umbone to about a third of the length of the shell, which would indicate septa 

 which probably supported processes peculiar to Camarophoria. We are also informed by 

 Professor M'Coy, that the shell occurs in brownish siliceous Carboniferous rocks, near 

 Shap Toll Bar, in England ; and Professor Do Koninck believes that the species is to be 

 found in the Carboniferous beds of Tournay, in Belgium. No Scotch example has been 

 recorded. 



Family — STROPHOMENIDiE. 



This family comprises several genera and sub-genera, of which Strophomena, Strepto- 

 rhjnchus, and Orlltis alone have been found to be represented in British Carboniferous 

 strata. It must however be remarked, that although the families Strop/iomenida and 

 Productida have been the subject of long and patient research, and that much progress 

 has been made towards their elucidation, a great deal still remains to be done before the 

 species of the first will have been grouped together with that degree of precision which is 

 required in similar investigations ; for it is certain that when we examine an extensive suit 

 of the species which are at present located in the genera Slrophomena and Lcptana, we 

 perceive much interior dissimilarity, and it would be desirable to group more closely 

 together those that resemble each other, and to separate those that are dissimilar. 

 This, however, is a subject for further consideration, and no good would accrue to science 



