﻿CAMAR0PH0R1A. 



117 



Obs. The above description has been abridged, or partly copied, from that published 

 by Professor M'Coy, in his work on * British Palaeozoic Fossils/ because, from not having 

 been able to obtain specimens of the species, I cannot express an opinion of my own as to 

 its specific value. It is, however, more than probable that the shell which was briefly 

 described, and vaguely represented, by M'Coy, in his ' Synopsis,' under the name of 

 Atrypa laticliva, is specifically distinct from the one he subsequently described and figured 

 as Camarophoria laticliva ; and although I have no means of ascertaining whether the 

 Professor is right while attributing the shell under description to the genus Camarophoria, 

 I have reproduced the name and figures under his responsibility alone. 



Professor M'Coy states, moreover, that " this species is very remarkable for its few 

 ribs, deep trilobation (accounting for the wide, steep, smooth spaces on each side of the 

 mesial ridges), and the very small beak. The smooth rostral space, free from ridges, 

 extending nearly to the beak, clearly separates this species from H. (B.) pleurodon ; and 

 their great size and small number are distinctive characters from C. ventilabrum. Some 

 very large specimens from Derbyshire, nearly ten lines long, show an obscure duplication 

 of some of the great ridges near the margin. The very small, depressed sides, wide space 

 free of ridges defining the mesial elevation, and the extremely sharp angular definition of 

 the ridges, separate the species from the obtuse H. (Rh.) pugnus. The mesial septum in 

 the (ventral) valve, in specimens of the above size, is from three to four lines long ; the 

 divarication forming the chamber in the beak is very distinct, but remarkably narrow, 

 being upwards of a line long, but considerably less than half a line wide. 



" Position and locality. Carboniferous limestone, Derbyshire ; and Lowich, Northum- 

 berland." 



Camarophoria isoryncha, M'Coy. PI. XXV, figs. 1, 2. 



Atrypa isorhyncha, M'Coy. Synopsis of the Characters of the Carboniferous Fossils of 



Ireland, p. 154, pi. xviii, fig. 8, 1844. 

 Camarophoria isorhyncha, M'Coy. British Palaeozic Fossils, p. 444, 1855. 



Spec. Char. Obscurely subcuboidal, globose ; length, width, and depth, nearly equal ; 

 dorsal valve very gibbous, presenting in profile a rising Curve, which is most elevated 

 close to the front, where it becomes suddenly deflected (at almost right angles), so as to 

 meet the margin of the opposite valve. The mesial fold is generally composed of four ribs, 

 but does not project very much above the uniform gibbosity of the valve ; the lateral 

 portions of the beak and umbone are compressed, flattened, or slightly concave. The 

 ventral valve is of small depth, and slightly convex to within a short distance of the front, 

 when it becomes suddenly bent so as to meet the margin of the opposite valve ; sinus 



