EUGNATH1DJK. 
305 
1837-39. Lepidotus jimbriatus, L. Agassiz, ibid. p. 247, pi. xxxiii. h 
(in part). [Scales; Oxford Museum.] 
1837. Semionotus rhombifer, L. Agassiz, ibid. p. 228, pi. xxvi a. [Im¬ 
perfect fisli; British Museum.] 
1849. Lepidotus jimbriatus , W. C. Williamson, Phil. Trans, p. 444. 
1849. Semionotus rhombifer , W. C. Williamson, ibid. p. 444, pi. xli. fig. 9. 
1868. Eulepidotus jimbriatus , Sir P. Egerton, Quart. Journ. Geol. Soc. 
yoL xxiv. p. 505. 
1872. Heterolepidotus latus, Sir P. Egerton, Figs. & Descript. Brit. 
Organic Remains, dec. xiii. (Mem. Geol. Surv.), no. 2, pi. ii. 
1887. Heterolepidotus jimbriatus, K. A. von Zittel, Handb. Palaeont. 
yoL iii. p. 204. 
1890. Eugnathus latus , Woodward & Sherborn, Catal. Brit. Foss. 
Vertebrata, p. 78. 
Type. Nearly complete fish ; British Museum. 
A large species, attaining a length of about 0-7. Length of head 
with opercular apparatus not quite equalling the maximum depth 
of the trunk and occupying about one-quarter of the total length 
of the fish; the depth of the caudal pedicle contained two-and-a- 
half times in the maximum depth. Cranium, facial bones, opercular 
bones, and the well-developed postclavicular scales ornamented 
with coarse and sparse tuberculations ; operculum about two-thirds 
as broad as deep, tapering above, and its maximum breadth 
equalling nearly one-third the length of the cranium ; marginal 
teeth robust and acuminate, and the teeth on the splenial bone rela¬ 
tively large anteriorly. Dorsal fin as long as deep, much larger 
than the anal fin, and arising opposite the origin of the pelvic pair. 
Principal scales of the anterior series on the flank slightly deeper 
than broad, and marked with fine ridges terminating in the serra¬ 
tions of the posterior border ; most of the flank scales and ventral 
scales as far as the origin of the dorsal and pelvic fins serrated, the 
others smooth. 
Though not clearly indicated by Egerton, this may be regarded 
as the type species of the genus Heterolepidotus. 
Form . Sf Loc. Lower Lias : Dorsetshire. F/- (UkjUL* 
All the following specimens were obtained from the neighbour¬ 
hood of Lyme Regis :— 
38118. The type specimen figured and described by Egerton, loc.cit. 
1872. Purchased , 1864. 
P. 2008. Large head with anterior abdominal squamation, displaying 
the opercular apparatus and post-clavicular plates, noticed 
by Egerton, ibid. p. 3. Egerton Coll. 
PART III. 
x 
