176 GANOID FISHES OF THE CARBONIFEROUS FORMATION. 



the lower lobe contains about fourteen rays, but the number of those in the upper one 

 cannot be accurately ascertained. 



Observations. — This very decidedly marked species closely resembles the foregoing 

 in the general form of the body and fins, in the shortness of the head with its large 

 orbit, and in the direction of the suspensorium ; but it may at the first glance be 

 distinguished by the bold and peculiar sculpture of the scales ; the ridges on the 

 head-bones are likewise different in character, and the dorsal and anal fins seem to be 

 somewhat more anteriorly placed. In addition to these diagnostic characters, an 

 examination of the head reveals certain osteological differences, which might easily be 

 considered to be of generic importance. Of these differences the most striking is the 

 form of the maxilla, which here (see Text-fig. 12) assumes a somewhat triangular form, 

 reminding us of that bone in the Platysomid Mesolepis, while in Canobius TLamsayi it is 

 not so much modified from the ordinary Palaeoniscid type. Our knowledge of the 

 osteology of the head of C. eler/antulus being still by no means complete, it will, I think, 

 be at present more convenient to be satisfied with the more obvious resemblances of 

 general configuration, and to leave this very pretty species, provisionally at least, in the 

 same genus with Canobius Mamsayi. 



Geological Position and Locality. — Not uncommon in the Low r er Carboniferous 

 (Calciferous Sandstone) fish-beds at Glencartholm, Eskdale. 



3. Canobius pulciiellus, Traquair. Plate XXXIX, figs. 7 — 11. 



Cakobius ruicuELLts, Traquair. Trans. Boy. Soc. Eclirib., vol. xxx, 1881, p. 51, 



pi. v, figs. 9—13. 

 — — A. S. Woodward. Cat. Foss. Fishes Brit. Mus., pt. ii, 1891, 



p. 432. 

 Mksopoma pulciiellum, Traquair. Arm. Mag. Nat. Hist. [6], vol. vi, 1S90, p. 493. 



Specific Characters. — Varying in length from 2\ to nearly 4 inches ; cranial 

 osteology more typically Palasoniscid than in the two previously described species. 

 Outer surfaces of cranial plates tuberculated, facial plates striated externally. Scales 

 highly ornate, there being first a band of ridges and furrows parallel with and close to 

 the anterior margin, then flexed below so as to become parallel with the lower margin 

 and with the set of transverse ridges and furrows which fill up the space above them on 

 the inferior, posterior and superior parts of the exposed surface of the scale (see figs. 8, 

 9, and 11 on PI. XXXIX). A median row of conspicuous scales extends from the 

 occiput to the commencement of the dorsal fin. 



Description. — The length of one absolutely entire specimen is 21 inches ; that of 

 a larger specimen deficient in the extremity of the upper lobe of the caudal fin is Sc- 

 inches. The length of the latter specimen when entire would probably amount to 

 5 inch more. 



