WOODWARD : FOSSIL FISHES OF THE UPPER LIAS OF WHITBY. 29 
Two distorted fishes associated on a small slab (pi. iii., fig. 3) 
are also interesting, the one as displaying the characteristic form of 
the dentary bone (d) with its ascending process, the other as showing 
more particularly the paired fins. The vertebral centra in these 
specimens are much deepened by crushing. The rays of the pectoral 
fins are not less than fifteen, and the rays of the pelvic fins at least 
ten in number. 
Another specimen worthy of note in this connection is the small 
contorted fisli shown in pi. iii., fig. 4. This is labelled by Agassiz, 
'* Leptolepis filipennis, Ag., Street," and is marked by Egerton as 
intended to be the type specimen of the species thus merely named. 
No true Leptolepis, however, has hitherto been discovered in the 
Lower Lias, vyhile the matrix of this specimen is identical with that 
of the fossil represented in fig. 1, even to the traversing veins of 
spar. The characters of the fish, so far as observable, are also 
identical with those of L. saltviciensis. The present writer thus feels 
justified in regarding it as a Whitby fossil, and in relegating 
L. filipennis, Ag., MS., to the synonymy of the species now under 
consideration. The head is very imperfect and a little elongated by 
crushing. The vertebrae are also fragmentary, but three of the 
simple constricted cylinders are seen immediately behind the pectoral 
fins, about as long as deep. The pelvic fins are further ^rom these 
than from the anal. The specimen is a little weathered and tinged 
with viviajiite. 
A distorted fish (Brit, Mus., No. 41724) with well-preserved 
caudal vertebrae, shows that the centra in this region are longer than 
deep (pi. iii., fig. 5) ; and a general consideration of all known 
specimens indicates that the total number of vertebrse is about forty, 
half abdominal and half caudal. In short, summarizing the charac- 
ters displayed by the numerous specimens available, it seems possible 
to formulate the following brief diagnosis of the species : — 
A small, slender species with delicate skeleton, attaining a 
length of about 0'07m. Length of head with opercular apparatus 
greatly exceeding the maximum depth of the trunk, which is con- 
tained about six times in the total length of the fish ; caudal pedicle 
comparatively robust, its depth about half the maximum depth of the 
