84 Proceedings of the Royal Physical Society. 



straight ribs or rounded ridges, which increase in number 

 proximally by bifurcation, and are not nodose. 



This spine, of which there are several specimens in the 

 Walker Collection, Edinburgh Museum, differs from Sph. 

 serridatus, Ag., by the multiplication of the lateral ribs by 

 bifurcation instead of intercalation. The want of nodosity 

 of these ribs is of no consequence, as the greatest difference 

 occurs in this respect in different individuals of >SpA. serrulatus, 

 and also of the closely allied Coal-Measure ioTm,Sph.hyhodoides 

 (Egerton). In a hard calcareous sandstone from the coast, 

 east of St Andrews. 



Ccelacanthopsis curta, n.g. and sp. (Plate V. Fig. 4). — 

 Of this interesting fish only one specimen has been obtained, 

 and that one is unfortunately deficient at the caudal ex- 

 tremity. What remains measures 2 inches in length, and 

 in this the length of the head is contained three times, being 

 also equal to the greatest depth. The head bones are crushed 

 and scarcely decipherable. Vertebral axis notochordal; 

 abdominal region extending for J inch behind shoulder- 

 girdle : no ribs are seen, but there is distinct evidence of 

 the ossified air-bladder characteristic of the Ccelacanthidae. 

 Neural arches united with the neural spines, which are very 

 long, very slender, and closely placed ; haemal arches and 

 spines similar in condition and configuration. On the dorsal 

 aspect, and just above the termination of the abdominal 

 cavity, a set of slender interspinous bones commences, these 

 being short at first but rapidly increasing in length, until 

 they are as long as the neural spines, and then the fish 

 suddenly breaks up about 2 inches from the tip of the snout. 

 Attached to the distal extremities of these interspinous 

 bones are fin-rays, very short anteriorly, and still short at 

 the point of truncation of the specimen. It is probable that 

 similar elements existed on the haemal aspect of the skeleton, 

 but have been lost. Paired fins not preserved, except a few 

 imperfect rays where the ventrals ought to be. Indications 

 of the presence of scales feeble. 



Strikingly new as this little fish is specifically, a word 

 or two must be said as to its family and generic relationship. 

 The ossified air-bladder, and the configuration of its neural 



