Br E. H. Traquair on Fossil Fishes from Oil Shales. 127 



shoulder and the commencement of the lower lobe of the 

 caudal fin, are of medium size, and in their general form are 

 similar to those of other species of Elonichthys. Their pos- 

 terior margins show, even as far back as the termination of the 

 dorsal fin, where the appearance tends to become obsolete, an 

 extremely delicate oblique serration, which distinguishes them 

 from the scales of every other species of the genus with which 

 I am acquainted, save E. tenuiserratics. Immediately behind 

 the shoulder girdle the scales are highly ornate, the free sur- 

 face being marked by delicate furrows, interrupted, inter- 

 calated, and mostly parallel with the lower margin, tending 

 also to pass into punctures posteriorly. Soon after passing 

 this region, the furrows become limited to the anterior margin 

 of each scale, and the greater part of the exposed area is 

 covered with thickly clotted punctures. 



The left pectoral fin is visible, as well as the anterior 

 margin of that of the right side, but both are only seen 

 through a thin layer of the matrix. They are acuminate in 

 shape, each as long as the lower jaw, and their principal rays 

 are clearly seen to be articulated up to their origins. Both 

 ventrals are also exhibited, but in indifferent preservation. 

 The dorsal is placed over the interval between the ventrals 

 and anal ; it is large, acuminate, and contains about thirty 

 rays. These dichotomise towards their terminations; their 

 articulations are longer than broad in the proximal halves of 

 the longer rays, but distally, and in the short rays of the 

 hinder part of the fin, they become very short. These ray- 

 joints, brilliantly ganoid, are each marked by a longitudinal fur- 

 row, in front of which again are usually a few oblique streaks, 

 the posterior margin being, like that of the scales of the body, 

 ornamented by a delicate oblique serrature, the denticles of 

 which point upwards and backwards. The anal fin is some- 

 what smaller than the dorsal, but possesses the same general 

 configuration, and the same mode of ornamentation of its 

 rays. The caudal is unfortunately very badly preserved as 

 regards clearness of detail, though its general shape — strongly 

 heterocercal and inequilobate — is traceable, partly in impres- 

 sion, partly as seen through a thin layer of matrix similar to 

 that which has obscured the head bones, as well as portions 



