LEPIDOTUS. 33 



and its tapering upper end is in contact with the lower part of the supraclavicle. 

 The second plate, directly beneath the first, is not much deeper than wide, with a 

 gently rounded postero-inferior angle ; the third plate (not seen in the specimens 

 figured, but shown in Text-fig. 14) is directly in front of the second plate, com- 

 paratively small and triangular in shape. The pectoral fin, as shown in PI. VI, is 

 rather large, the longest of its sixteen or seventeen closely pressed rays almost 

 reaching the origin of the pelvic fins. The fin is fringed in front with a paired 

 series of about eight enamelled fulcra, and all the rays, which are almost without 

 enamel, are articulated and divided in their distal half. The pelvic fins nearly 

 resemble the pectorals, but are much smaller, with only seven rays, of which the 

 longest attains about three-quarters of the length of the longest pectoral. The 

 dorsal and anal fins are characterised by their very stout fulcra, which are covered 

 with smooth enamel and paired like those of the pectoral and pelvic fins. In the 

 dorsal fin, four, five, or even six stout fulcra of gradually increasing length are 

 directly inserted in the ridge of the back, and their long crowded supports (causing 

 a break in the squamation in PI. VI) penetrate the muscles almost as far as the 

 position of the notochord. As shown in PI. VI, the length of the longest of these 

 fulcra much exceeds half the extreme height of the fin ; while there are also a few 

 large fulcra fringing the foremost ray. The rays are about eleven or twelve in 

 number, closely arranged and rapidly diminishing in size backwards, each articulated 

 and finely divided in the distal half : they are destitute of enamel or marked only 

 by the slightest streak. The anal fin, with ten rays, nearly resembles the dorsal 

 in shape, but it is much smaller and its anterior fulcra are less stout, only two or 

 at most three being directly inserted in the ridge of the body. The great support 

 for the fulcra, however, is deeply inserted in the muscles of the trunk (PI. VII, 

 fig. 5(7,/..s".). The caudal fin consists of about eighteen comparatively stout rays, 

 which are closely articulated and divided nearly to the base, and differ from the 

 other fin-rays in being well covered with enamel in their basal half. The fin is 

 slightly excavated behind (as shown in B. M. no. 19006), and its fringing fulcra 

 are about as large as those of the anal fin. 



All the scales are smooth, sometimes with a faintly concave face ; and their 

 hinder margin is often slightly convex, while their upper and lower margins are 

 sigmoidally curved. None of the principal flank-scales are much deeper than 

 broad, but they are comparatively deeper in the typical stout forms (PI. VI) than 

 in the more slender forms (Text-fig. 14). They also appear sometimes smaller in 

 the former than in the latter, but the total number of transverse series of scales is 

 always approximately the same (about thirty-eight to forty as counted along the 

 lateral line), while the number in a series above the origin of the pelvic fin is 

 nineteen or twenty. In this position the lateral line always traverses the eleventh 

 scale from the ventral border ; while above the origin of the anal fin it traverses the 

 thirteenth or fourteenth scale in the stout forms (PI. VI), the ninth scale in the 



