WELLBURX : ON THE GENUS MEGALICHTHYS, AGASSIZ. 67 
There are two dorsal fins, the second being the larger and more 
powerful; the first rises at a point about equal to five-eighths 
the total length of the fish, measuring from the snout, the second 
being about three-sixteenths further back ; the first is opposed 
to the ventral and the second to the anal fin, which is smaller 
than the others and more lanceolate in shape, and is situated 
close to the origin of the caudal fin. All these fins are lobate, 
the lobe being more acute than that of the paired fins, and 
well-marked fulcral scales are also present. The caudal fin is 
powerful, and intermediate in type between the diphycercal and 
heterocercal stages ; its posterior margin slopes obliquely upwards 
and backwards, and the majority of the dermal rays spring from 
the under side of the body prolongation. The fish was evidently 
very powerful, and of predaceous habits. 
Note. — The proportions of certain of the bones of the head 
vary, as shown in the following table : — 
Parietal Division of 
Cranial Roof. 
Maxilla. 
Mandible. 
M. Hibherti Ag. | 
, , intermedins A. S. W. | 
pygmctus Tr. 
,, laticeps Tr. ... -| 
Longer than the 
Fronto- Ethmoi- 
dal dhision. 
Do. { 
Shorter than the 
Fronto-Ethmoi- 
dal division. 
Three times as 
long as great- 
est depth. 
Posterior expan- 
sion deep. 
, J 
■ \ 
More than four 
times as long as 
deep. 
] Five times as 
j" long as deep. 
} Do. 
Three and a half 
times as long as 
deep. 
1 Do. 
Before concluding this paper I must acknowledge, with 
warmest thanks, the great obligation I am under to the following 
gentlemen for the privilege of examining the specimens under 
their care, viz., Dr. R. H. Traquair, F.R.S., Mr. A. Smith 
Woodward, F.G.S., Dr. C. B. Crampton (Owens College), Mr. 
Crowther (Leeds Museum), and Mr. Rowe (Brighouse). 
