E 
GHOLOGICAL MAGAZINE 
NEW SERIES. DECADE VI. VOL. Ill. 
No. II.—_ FEBRUARY, 1916. 
ORIGINAL ARTICLES. 
I.—On a New Specimen oF tHE Liassic Pacnycormip FIsH 
SAUROSTOMUS ESOCINUS, AGASSIZ. 
By A. SMITH WOODWARD, LL.D., F.R.S., Pres. Geol. Soc. 
(PLATE II.) 
LTHOUGH the Pachycormid fish Saurostomus esocinus was 
A known only by part of a lower jaw from the Upper Lias of 
Baden when it was first named by Agassiz, its principal characters 
have since been revealed by many incomplete specimens from the 
Upper Lias of Wiirtemberg, France, and Yorkshire, and by a well- 
preserved fish from Ilminster, Somersetshire, in the Charles Moore 
Collection, Bath Museum.! The internal skeleton of the trunk and 
the fins, however, have not hitherto been so well seen as in a nearly 
complete fish from the Upper Lias of Wiirtemberg, prepared by 
Mr. Bernhard Hauff and now in the British Museum. 
This new specimen, which measures about 1:4 m. in total length, is 
shown of about one-eighth the natural size in Plate II. The head is 
deepened by crushing, so that the roof is pushed upwards above and 
‘the gular plate downwards below ; but it is obviously shorter and 
wider than that of Pachycormus, while the snout is comparatively 
blunt. The external bones are thin and of fibrous texture, and are 
thus crushed on the stouter inner elements in a confused mass, but 
- afew features are recognizable. A notch in one bone which seems 
to be nasal may be regarded as marking the narial opening. The 
blunt rostral region is shown in front view, with a row of small 
conical teeth along the oral border as already observed in a Whitby 
specimen. The large orbit is indicated by an ossified sclerotic in 
two halves, anterior and posterior. The cheek-plates are obscured by 
their crushing on the mandibular suspensorium and pterygo-palatine 
bones; but it is clear that although the hyomandibular is inclined 
backwards, the quadrate turns as sharply forwards, so that the 
mandibular articulation is not far behind the orbit. Below the cheek 
the long and slender maxilla is conspicuous, a little downwardly 
curved in its hinder portion, where its upper border is overlapped by 
a single long and narrow supramaxilla. The maxilla bears the usual 
large conical teeth in a spaced series, flanked outside by a close series 
of comparatively minute teeth, as in Hypsocormus. A cluster of 
rather large teeth, of the palatine or other inner element, is also seen 
between the maxilla and displaced premaxilla. In the mandible the 
1 For references to literature see Catal. Foss. Fishes Brit. Mus., pt. iii, 
p- 388, 1895; also A. S. Woodward, ‘‘ Fossil Fishes of the Upper Lias of 
Whitby,’’ Proc. Yorks. Geol. and Polyt. Soc., vol. xiii, p. 158, pl. xx, 1896. 
DECADE VI.—VOL. II.—NO. II. 4 
