282 
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 (tig. 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 endoskeletal 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, M/ter. 
[Plate VII.] 
1829. “ Trionyx Sedgwick & Murchison, Trans. Geol. Soc. [2] vol. iii. 
p. 144, pi. xvi. fig. 6. 
cus/>sdo.fus/ 1841. Coccosteu^ H. Miller (ex Agassiz, MS.), Old Red Sandst. pi. iii. f 
1842. Coccosteus latus , L. Agassiz, Rep. Brit. Assoc, p. 87j name only). 3 
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. a. fig. 2. [Imperfect skeleton ; British Museum.] 
