Dr. R. H. Traquair — Fifcs//ire Caydoniferons Fishes. IV* 



of St. Andrews. Owing to the hardness of the matrix it was 

 impossible to work out the superficial configuration of the teeth, 

 except in two instances where they happened to be covered by 

 white carbonate of lime. 



Sphenacantlms Fifensis, n.sp. — Length of the largest specimen, 

 5f inches ; greatest antero-posterior diameter, | inch ; implanted 

 portion reaching up to 1 {; inches in front and 2£ inches behind ; 

 form straight and tapering ; posterior area slightly concave, its 

 margins showing traces of abraded denticles ; anterior margui of 

 exserted portion formed by a sharp median ridge ; sides ornamented 

 by 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. serrtdatiis, Ag., 

 by the multiplication of the lateral ribs by bifurcation instead of 

 intercalation. The want of nodosity' of these ribs is of no con- 

 sequence, as the greatest difference occurs in this respect in different 

 individuals of Sph. serrulatus, and also of the closely allied Coal- 

 measure form Sph. hyhodoides (Egerton). In a hard calcareous 

 sandstone from the coast east of St. Andrews. 



Coelacanthopsis curta, n. g. and sp. — Of this interesting fish only 

 one specimen has been obtained, and that one is unfortunately 

 deficient at the caudal extremity- 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 ^ inch behind shoulder-girdle ; no 

 ribs are seen, but there is distinct evidence of the ossified air-bladder 

 characteristic of the Coelacanthidse. Neural arches united with the 

 neural spines, which are 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 hernial 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 relationships. The ossified 

 air-bladder and the configuration of its neural and hfemal arches 

 and spines at once indicate that its family position is in the Coela- 

 canthidfe, but its differences from any known genus of this famil}- 

 are very strongly marked. We have, firstly, the abbreviated form of 

 the fish, which is certainly not entirely due to post-mortem shortening 

 up, as the skeletal parts in front of the place where the specimen 



DECADE IV. VOL. VIII. — Xo. III. 



