88 GANOID FISHES OF THE CARBONIFEROUS FORMATION. 



14. Elonichthys denticui-atus, Traquair. Plate XX, figs. ] — 2. 



Elonichthys denticulatus, Traquair. Geol. Mag. [5], vol. iii, 1900, pp. 556, 557. 



Description. — The remains of a Palsconiscid fish from the Lower Carboniferous rocks 

 of Flintshire, submitted to me by Mr. J. T. Stobbs, F.G.S., are unfortunately not 

 sufficiently perfect to afford material for a complete diagnosis. The specimen shows the 

 impressions of the outer surface of both mandibular rami and of the left maxilla, and 

 beyond this we have only a mass of dislocated scales — the general form of the fins, and 

 the condition of the fin-rays being entirely lost. 



The mandible is three quarters of an inch in length, slender and tapering, the 

 external sculpture, according to the impression left, consisting of fine close ridges, 

 which, in feather fashion, diverge upwards and forwards and downwards and forwards 

 from a line running longitudinally along the middle of the surface, thus forming a series 

 of backwardly directed acute angles. The maxilla is of the usual Palreoniscid form, the 

 suborbital process being long and slender, and the expanded post-orbital portion 

 ornamented, as shown by the impression, with fine ridges, which mostly run parallel 

 with the posterior and superior borders. 



Among the scales may be distinguished some which are nearly equilateral and only 

 slightly oblique — these belonged to the flank ; others, longer than high, were ventral in 

 position ; while others again, smaller in size and more oblique in contour, appertained 

 to the tail. The flank scales (PI. XX, fig. 1) are about one tenth of an inch in 

 height and have nearly the same breadth ; the overlapped area is scarcely perceptible ; 

 the free surface is marked with fine striae, which run mostly parallel with the upper and 

 lower margins, a very few of the lowest ones turning up in front so as to run parallel 

 with the anterior margin; while again a number of deeper indentations divide the 

 posterior margin into six to eight strong and sharp denticulations. The ventral scales 

 (fig. 2), being lower in contour, have fewer denticulations on the hinder border, these 

 numbering from three to five. As to the caudal scales, though it is evident that they 

 remained highly ornate up to the extremity, it is not clear how far posteriorly the 

 denticulated character persisted. 



Remarks. — The configuration of ihe mandible and maxilla clearly proves that the 

 position of the present fish is in the family Palaeoniscidae, but owing to the complete 

 absence of fins or fin-rays the evidence as to the genus is not conclusive. According to 

 the form and sculpture of the scales the fish might appertain either to Bhadinichlhys or 

 to Elonichthys. Perhaps the scales have the greatest resemblance in sculpture to those 

 of Elonichthys Egertoni (Egerton), but the denticulations of the posterior margin are 

 proportionally coarser. Anyway, the association on these scales of fine stria3 with 

 comparatively coarse denticulations of the hinder margin is a feature which leads me to 



