204 The True Sharks 
fishes. They are, however, nowhere very common. The teeth 
of Dalatias major exist in Miocene rocks. In the genus 
Somniosus the species are of very much greater size, Somniosus 
microcephalus attaining the length of about twenty-five feet. 
This species, known as the sleeper-shark or Greenland shark, 
lives in all cold seas and is an especial enemy of the whale, from 
which it bites large masses of flesh with a ferocity hardly to be 
expected from its clumsy appearance. From its habit of feeding 
on fish-offal, it is known in New England as “gurry-shark.”’ Its 
small quadrate teeth are very much like those of the dogfish, 
their tips so turned aside as to form a cutting edge. The species 
is stout in form and sluggish in movement. It is taken for 
its liver in the north Atlantic on both coasts in Puget Sound 
and Bering Sea, and I have seen it in the markets of Tokyo. In 
Alaska it abounds about the salmon canneries feeding on the 
refuse. 
Family Echinorhinide.—The bramble-sharks, Echinorhinide, 
differ in the posterior insertion of the very small dorsal fins, 
and in the presence of scattered round tubercles, like the thorns 
of a bramble instead of shagreen. The single species, Echinorhi- 
nus spinosus reaches a large size. It is rather 
scarce on the coasts of Europe, and was once 
taken on Cape Cod. The teeth of an extinct 
species, Echinorhinus richardi, are found in the 
Pliocene. 
Suborder Rhine.—The suborder Rhine in- 
cludes those sharks having the vertebre tecto- 
spondylous, that is, with two or more series of 
calcified lamella, as on the rays. They are 
transitional forms, as near the rays as the 
sharks, although having the gill-openings rather 
lateral than inferior, the great pectoral fins 
being separated by a notch from the head. 
The principal family is that of the angel- 
fishes, or monkfishes (Squatinide). In this 
group the body is depressed and flat like that ein Ge 
of aray. The greatly enlarged pectorals form — squatina L. “(After 
a sort of shoulder in front alongside of the ee 
gill-openings, which has suggested the bend of the angel’s wing. 
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