LEPTOLEPIS. 123 



1845. Oxygonius tenuis, L. Agassiz, in P. B. Brodie, op. cit., p. 16, pi. i, fig. 4. 



1850. Sarginites pygmseus, O. G. Costa, Atti Accad. Pontan., vol. v, p. 285, pi. vi, figs. 6 — 8. 



1850. Megastoma apenn.imim, O. G. Costa, loc. cit., vol. v, p. 287, pi. vi, figs. 9, 10. 



1853. Sarginites pygmseus, O. G. Costa, loc. cit., vol. vii, p. 7, pi. i, fig. 4. 



1853. Megastoma apenninum, O. G. Costa, loc. cit., vol. vii, p. 8, pi. i, fig. 3. 



1879. Leptolepis neocomiensis, F. Bassani, Verhandl. k. k. geol. Keichsanst., p. 164. 



1882. Leptolepis neocomiensis, F. Bassani, Denkschr. k. Akad. Wiss. Wien, math.-naturw. CI., 



vol. xlv, p. 204, pi. ii, figs. 1 — 5. 

 1895. Leptolepis brodiei, A. S. Woodward, Geol. Mag. [4], vol. ii, p. 150, pi. vii, figs. 5, 6 ; also Catal. 



Foss. Fishes Brit. Mus., pt. iii, p. 515. 

 1912. Leptolepis brodiei, F. Bassani and G. D'Erasmo, Mem. Soc. Ital. Sci., XL [3], vol. xvii, p. 229, 



pi. iv, fig. 6. 

 1915. Leptolepis brodiei, F. Bassani and G. D'Erasmo, Palaeont. italica, vol. xxi, p. 12, pi. i, figs. 4 — 6. 



Type. — Imperfect fish ; British Museum. 



Specific Characters. — A small species, attaining a length of about 5 cm., but 

 usually smaller. Length of head with opercular apparatus exceeding the maximum 

 depth of the trunk, and contained about four times in the total length of the fish ; 

 width of caudal pedicle at least half the maximum depth of the abdominal region. 

 Vertebrae from 40 to 45 in number, about half being caudal ; the centra smooth ; 

 the neural and haemal spines in the caudal region nearly straight. Pelvic fins 

 arising about midway between the pectoral and anal fins, opposite to the anterior 

 half of the dorsal, which has 10 or 11 bifurcated rays besides 2 or 3 shorter 

 simple rays in front ; anal fin with about 7 rays, arising nearer to the caudal than 

 to the pelvic fins. 



Description of Specimens. — The type specimen, which is shown enlarged in 

 PL XXIII, fig. 3, is a little distorted by the crushing upwards of the ventral border 

 of the hinder abdominal region, while its caudal region is imperfect and lacks the 

 caudal fin. The clavicles of the fish may also be slightly crushed backwards. It 

 shows, however, most of the characteristic features of the species. The second 

 specimen figured by Brodie is similarly crushed, and is important as displaying 

 the distinctive shape of the dentary bone (PL XXIII, fig. 4). Other specimens in 

 the Brodie Collection, and still finer examples discovered by the Rev. W. R. Andrews, 

 nearly complete our knowledge of the species. Two of these seem to show the 

 true shape of the trunk and the proportions of the caudal fin (PL XXIII, figs. 5, 6). 



All these fishes have the appearance of immaturity, Avith a relatively large 

 orbit, which is often marked by a black stain. The head and opercular bones are 

 smooth, and the slime-canals are relatively large, as shown especially by the frontals 

 when exposed from below (B.M. no. P. 7635). The slender parasphenoid is nearly 

 straight, but curves upwards a little both in front and behind. The mandibular 

 suspensoriuni is inclined much forwards, so that the articulation is beneath the 

 middle of the orbit. In one specimen discovered by Rev. W. R. Andrews (B.M. 

 no. P. 6305) minute teeth seem to occur on the slender arched maxilla, which has 



