158 WOODWARD : FOSSIL FISHES OF THE UPPER LIAS OF WHITBY. 
Family PACHYCORMiDiE. 
Saurostomus esocinus, Agassiz. 
Plate XX. 
1833-4i. Saurostomus esocinus, L. Agassiz, Poiss. Foss., vol. ii., 
pt. i., p. 14 ; pt. ii., p. 144, pi. Iviiib., fig. 4. 
1 844. Eugnathus giganteus = Pachycm-miis giganteus, L. Agassiz, 
ibid., pt. ii., pp. 104, 114 (undefined). 
1844. Pachycormus latirostris, L. Agassiz, ibid., pt. ii., p. 114. 
1848. Pachycormus esocinus, C. G. Giebel, Fauna der Vorwelt, 
Fische, p. 197. 
1848. Pachycormus latirostris, C. G. Giebel, ibid., p. 198. 
1848. Eugna.thus giganteus, C. G. Giebel, ibid., p. 238. 
1858. Pachycormus bollensis, F. A. Quenstedt, Der Jura, p. 237, 
pi. xxxii., fig. 6. 
(?) 1878. Pachycormus westermani, T. C. Winkler, Archiv. Mus. 
Teyler, vol. v., p. 9, pi. i. 
1891. Caturus gigas, H. E. Sauvage, Bull. Soc. Hist. Nat. Autun, 
vol. iv., p. 74, pi. vii. 
1895-96. Pachycormus {Saurostomus) esocinus, A. S. Woodward, 
Catal. Foss. Fishes, B.M., pt. iii., p. 388 ; and Proc. Bath 
Nat. Hist, and Antiq. Field Club, vol. viii., p. 241, 
Type: Dentary bone of fish. 
Among the numerous ganoid fishes mentioned though not des- 
cribed by Agassiz in his great work, is a large member of the family 
Pachycormidse, which he records under the name of Pachycoi^mus 
latirostris. The only brief notice of this fish is as follows : — " Tres 
grande espece, plus grande que le P. macropterus, mais a tete courte 
et a museau pointu. Du lias de Whitby." No further account of 
the species has hitherto been published, but the original specimens on 
which it was founded in the Enniskillen and Egerton Collections, are 
now in the British Museum, and it is thus possible to determine 
exactly what Agassiz meant by the name in question. Careful com- 
parison seems to show that a detached mandible which he had 
previously described from the Upper Lias of Baden under the name 
of Saurostomus esocinus, truly belongs to the same fish. Comparatively 
well-preserved specimens from the same horizon in Wiirtemberg, and 
