WOODWARD : FOSSIL FISHES OF THE UPPER LIAS OF WHITBY. 157 
The specimen in the Keed Collection, York Museum, is some- 
what smaller than that just described, but seems to belong to the 
same species. It comprises the head, anterior abdominal region, and 
the base of the left pectoral fin ; but it is obliquely crushed from 
above, and thus much fractured and distorted. The frontal bones 
appear to be as ah'eady described. The squamosal, preserved on each 
side, exhibits only structural markings, and has a wide margin of 
overlap for the supratemporals, of wliich only fragments remain. 
The posterior upper suborbital is shown in impression on the left side 
and seems to resemble that of the first specimen in form and pio- 
portions ; but the other cheek-plates are displaced and not sufficiently 
well preserved for description. A fragment on the right side exhibits 
the extremely delicate rugose ornament noted on the suboperculum 
of the previous specimen. The greater part of the maxilla is exposed 
on the right side ; it is shown to be very slender, very slightly arched, 
and not much deepened behind. The supramaxilla, partly shown on 
both sides, is shaped as in the first specimen. The mandible is 
complete, obscured in the coronoid region, but displaying its slender 
tapering form in front. The angular bone (pi. xix., fig. 2, ag.) is short 
and small ; the dentary {d.) clearly exhibits some of the teeth, those 
of the middle of the right side being long, not much expanded at the 
base, a little curved inwards or forwards at the apex (fig. 2a). 
Between the mandibular rami the large gular plate {gu.), chiefly in 
impression, is conspicuous, and this would extend about two-thirds 
the length of the mandible. The stout branchiostegal rays {br.) 
with traces of the longitudinal striations, remain in imperfect series 
behind. Those on the left side are best preserved, and seem to have 
been 18 in number. The opercular apparatus is too imperfect for 
description, and the pectoral arch is obscured ; but a large part of 
the base of the left pectoral fin {pet.) is preserved. The unjointed 
bases of 14 stout rays are shown, the foremost straight and marked 
with the characteristic longitudinal ribbing. The scales {s.) are 
marked only by the concentric lines of growth. Those of the ventral 
aspect (fig. 2, s. ) are equilateral, while those of the upper part of the 
flank (fig. 2 b.) are considerably deeper than broad. 
