16 



BRITISH FOSSILS. 



i have examined specimens of C. HassicB and C. granulatiis in 

 Lord Ennisldllen^s collection. They are undoubted Coelacanths, 

 a specimen of C, Hassice exhibiting the characteristic anterior 

 dorsal interspinous bone, but no scales were preserved in any of 

 the examples, nor were they in such a state as to allow of any 

 useful comparison of the proportions of the body and fins. 



C. caadalis is discussed below. Of C. minor I have seen no 

 specimen, and Prof Agassiz' diagnosis is insufficient to enable 

 me to give any opinion concerning its specific distinctness. 



Again, the differences between the genera Ccelacanthus and 

 Undina appear to me to be anything but clearly made out. The 

 close similarity of the two genera in the broad features of their 

 structure is indubitable ; and it is open to doubt whether the 

 differences in the dentition are not more apparent than real. 



Under these circumstances I shall adopt the generic and specific 

 names, which have been used by my predecessors, provisionally, and 

 without intending, for the present, to express any opinion as to 

 their real value. 



/. Ccelacanthus lepturus, Agassiz. 



No. 1. The specimen represented in PL II. , Jigs. 1, 2, 3, 4. 



This fossil fish is nearly entire, only a small portion of its caudal 

 extremity being absent. Its total length could not have exceeded 

 five inches. 



The length of the head appears to have been about 1'3 in., but 

 the snout is somewhat crushed, and the occipital boundary is but 

 indistinctly indicated. 



The depth of the body, at the level of the anterior edge of the an- 

 terior dorsal fin {D) is 0*95 in. The anterior dorsal fin itself is 0*75 in. 

 distant from the occiput, and 0*2 in. broad at its base. Twelve 

 stout fin rays can be. counted in it, the anterior three being shorter 

 than the others, and gradually increasing in length to the fourth, 

 which is about 0*75 in. long. I can discern no ornamentation 

 upon any of these fin rays, which appear to be quite smooth, and 

 become divided into broad quadrate joints in their distal moieties. 



The remains of a large interspinous bone are seen at the base of 

 the dorsal fin rays, and supporting them. 



The fin rays of the second dorsal have disappeared, but I believe 

 I can perceive indications of its interspinous bone. 



The caudal fin (C) is very imperfect ; tl)e anal and pectoral fins 

 are absent ; but the right ventml ( V) is seen in place, a little behind 

 the level of the anterior dorsal. It is a considerable fin, as large 

 as the anterior dorsal itself. 



The scales of this fish are thin, flat, cycloidal, and 0*15 to 

 0*2 in. in diameter. The middle of the posterior margin of many 

 of the scales (figs. 3 and 4) is produced, so that the exposed portion 

 is nearly triangular. The sculpture consists of raised, continuous, 

 ridges, which converge towards the middle line. 



