﻿100 



BRITISH CARBONIFEROUS BRACHIOPODA. 



which, although very defective and imperfect in drawing, conveys some idea of the 

 arrangement. 



The intimate shell structure does not differ in any respect from that which is common 

 to its congeners. 



In 1825, Sowerby represented several examples or variations in shape of the shell 

 under description, observing, at the same time, that out of several hundred specimens, 

 hardly two could be found alike; he mentions, likewise, that Ter. lateralis (' Min. Con.,' 

 tab. lxxxiii, fig. 1), may probably be a variety or shape of B. pugnus ; but as the 

 original specimen could no longer be found in the Sowerby collection, and as the figure 

 is insufficient, all that can be said is, that whether the specimen be referable to B. pugnus, 

 or to B. angulata, it will require to be added to the synonyms. 1 



In 1836, Professor Phillips described and figured a Rhynchonella by the name of 

 T. sulcirostris. " Rhomboideo-deltoidal ; edge sharp, plaits obtuse, mesial plaits five to 

 nine; upper valve (our dorsal) sulcate towards the beak" 2 (fig. 16, of my plate) ; and I 

 have felt much puzzled how to deal with this species (?), for I could not satisfactorily 

 recognise the original specimen, in the Gilbertsonian collection, all those bearing the 

 name sulcirostris appearing to be nothing more than variations in shape of B. pugnus, in 

 which the ribs on the fold and sinus have extended to ne rly the extremity of the beak, 

 and thus agreeing also with what we perceive to have been the case with Martin's type. 

 B. sulcirostris appears to be one of those undecided shapes, bearing some resemblance to 

 B. pleurodon, of which Mr. Morris has supposed it a synonym ; but the shortness of the 

 lateral ribs, as depicted in the figure, would assimilate it more closely to certain varieties 

 of B. pugnus, than to B. pleurodon, which does not present that appearance. It appears 

 to me, however, almost certain that the shell in question is a true Bhynchonella, and not a 

 Camarophoria, as described by Professor M'Coy, at p. 446 of his ' British Palaeozoic 

 Fossils,' and it is evident that the last-named author must have had before him some 

 other species while drawing up his description ; but as he does not furnish us with a 

 representation of his shell, it is impossible for me to offer any further opinion on the sub- 

 ject. It must also be remarked that the large specimen drawn in pi. xii, fig. 16, of the 

 ' Geology of Yorkshire,' would be more properly located with B. pugnus, than with B. 

 pleurodon. 



The description and figure Professor M'Coy gives us of his Atrypa laticliva, at p. 154 s 



1 I have reproduced Sowerby' s description of R. lateralis, under R. angulata, and the figure will be 

 found in PI. XXV, fig. 14. 



2 Phillips's ' Geology of Yorkshire,' vol. ii, p. 222. 



3 " Transversely rhomboidal, length two thirds the width, gibbous ; middle of the shell elevated in 

 front, with three obtuse ribs, reaching nearly to the beak ; between the mesial elevation and the sides is a 

 smooth space, equal in breadth to the mesial elevation ; sides small, compressed, with three obtuse ridges 

 reaching half way to the beak. This species is remarkable for the small number of ribs, and the broad 

 space between those of the mesial elevation and the sides ; length G lines, width 9 lines." 



