﻿2S2 



ABTHRODIRA. 



As already remarked, the pectoral arch seems to be represented 

 by a large pair of dermal bones, but no appendages are observable. 

 There is, however, distinct evidence of a hinder pair of limbs (see 

 p. 289), and the well-developed pelvic basipterygia (fig. 44), super- 

 ficially calcified, and separated in the middle line below, are often 

 conspicuous. At the broad lower end these exhibit one or two 

 deep pits or foramina. In each pelvic fin there is a proximal series 

 of four or five short basal cartilages, and distal to these is another 

 series of elongated cartilages, all robust and superficially calcified, 



Pig. 44. 



Coccosteus decipiens, Ag. ; side view, restored. 



but arranged in a manner that is not yet clearly shown : it can 

 merely be determined that the fin possessed a well-developed base 

 of endeskeletal elements. 



A singular thin, quadrate plate, with rounded angles and pro- 

 minent concentric lines of growth, also occurs in the abdominal 

 region (fig. 44) immediately behind the much elongated haemal 

 arches. To the present writer it is most suggestive of an internal 

 element of support occurring in the vertical septum between the 

 right and left halves of some paired organ. 



Coccosteus decipiens, Agassiz. 



[Plate VII.] 



1829. " Trionyx* Sedgwick & Murchison, Trans. Geol. Soc. [2] vol. iii. 

 p. 144, pi. xvi. fig. 6. 



1841. Coccosteus, H. Miller (ex Agassiz, MS.), Old Red Sandst. pi. iii. 



1842. Coccosteus latus, L. Agassiz, Rep. Brit. Assoc, p. 87 (name only). 

 1842. Coccosteus cuspidatus, P. Duff (ex Agassiz, MS.), Geol. Moray, 



p. 69, pi. viii. fig. 1, 

 1844. Coccosteus decipiens, L. Agassiz, Poiss. Foss. V. G. R. pp. 26 ; 



137, pi. B. figs. 2, 3, pis. vii.-x., pi. xxx. a. fig. 19. 

 1844. Coccosteus oblongus, L. Agassiz, ibid. p. 28, pi. xi. figs. 1-3, 



pi. xxx. «. fig. 2. [Imperfect skeleton ; British Museum.] 



