388 
ACTINOPTERYGII. 
32435. Small head and left pectoral fin, this displaying three basal 
fulcra and a close series of minute fulcra beyond ; Curcy. 
Tesson Coll. 
32432, 32434. Two small heads, the first displaying the branchio- 
stegal rays, the second exhibiting the cranium and cheek- 
plates ; Curcy. Tesson Coll. 
32437-39, 39 a. Four fragmentary heads with anterior scales, those 
of the last specimen faintly rugose ; Curcy. Tesson Coll. 
35583. Remains of head and trunk either of this species or P. acuti- 
rostris ; Whitby. Purchased, 1859. 
Pachycormus (Saurostomus) esocinus (Agassiz). 
1833-44. Saurostomus esocinus, L. Agassiz, Poiss. Foss. yoI. ii. pt. i. 
p. 14 ; pt. ii. p. 144, pi. lviii. b. fig. 4. 
1844. Eugnathus giganteus — Pachycormus giganteus, L. Agassiz, ibid. 
pt. ii. pp. 104, 114 (undefined). [Imperfect fish; British Museum.] 
1844. Pachycormus latirostris , L. Agassiz, ibid. pt. ii. p. 114. [Imper¬ 
fect head ; British Museum.] 
1848. Pachycormus esocinus, C. G. Giebel, Fauna d. Yorw., Fisclie, 
p. 197. 
1848. Pachycormus latirostris , C. G. Giebel, ibid. p. 198. 
1848. Eugnathus giganteus , C. G. Giebel, ibid. p. 238. 
1858. Pachycormus bollensis, F. A. Quenstedt, Der Jura, p. 237, pi. xxxii. 
fig. 6. [Imperfect fish; Tubingen University Museum.] 
(?) 1878. Pachycormus westermani, T. C. Winkler, Archiv. Mus. Teyler, 
vol. v. p. 9, pi. i. [Imperfect fish; Teyler Museum, Haarlem.] 
1891. Caturus gigas, II. E. Sauvage, Bull. Soc. Hist. Nat. Autun, 
vol. iv. p.74, pi. vii. [Head.] 
Type. Dentary Done; olim Walchner Coll. 
A large species, attaining a length of not less than 1*0. Head 
with opercular apparatus occupying one-quarter of the total length 
of the fish; head very short and stout, and teeth relatively larger 
than in the other species ; operculum as broad as deep, trapezoidal 
in form, and the upper border shortest; branchiostegal rays some¬ 
what less than 40 in number. Dorsal and anal fins about equally 
extended, with not less than 30 rays, the latter arising just in 
advance of a point opposite the hinder end of the former. Scales 
of the lateral line on the caudal region somewhat enlarged. 
This is the type species of the so-called genus Saurostomus , and 
further researches must determine definitely whether or not its 
universally-accepted reference to Pachycormus is correct. The 
characteristic median elevation of the parieto-occipital region of the 
