186 BACKBONED ANIMALS. 
to time, and either eggs or newly-hatched young may be found in the 
cavity of the gills or the space inclosed by the branchiostegal mem- 
brane. The unhatched eggs, according to Agassiz, are always found 
in the same position in the curious nursery—namely, in the upper part 
of the branchial arches, protected or held together by a special Jobe or 
valve formed of the upper pharyngeals. Here they are held until the 
young are able to care for themselves. 
Sculpins (Cot#ide)—These are marine fishes of fan- 
tastic shape, each individual often varying in color. The 
head and opercular bones are armed with sharp spines, 
and the fishes resemble the mossy rocks amid which they 
lie. The sea-raven, or yellow sculpin, is an allied form, 
attaining a length of two feet, and is remarkable for its 
grotesque coloring. The males of some species erect nests 
for their young. Allied are the sea-robins (Zviglida). 
The flying-robin (Dactylopterus) has enormous pectoral 
fins by which it soars over the water like the flying-fish, 
Sailors have been knocked over by them, and they are 
frequently blown aboard vessels. 
Gobies (Godiidz)—The gobies are small fishes, in 
which the thoracic ventrals are united, forming a hollow 
disk. They have no air-bladders, and are remarkable for 
their habit of leaving the water. The scaleless and black 
gobies and several other species are found on the western 
coast of North America. 
Note.—In the Periophthalmus (frontispiece), common at the Feejee 
Islands, Ceylon, and other localities, the pectoral fins are greatly devel- 
oped, the head blunt, and the eyes staring and prominent. They leave 
the water and hop along the shore so fast that it is difficult to catch 
them, resembling frogs more than fishes. They feed out of water, pre- 
ferring a shell-less mollusk, the Oxchidium (Fig. 72), and insects. The 
Boleophthalmus has similar habits. The Blennius pholis also leaves 
the water at times. The black goby is said to build a nest for its eggs. 
Lump-Fish (Cyclopteridz).—The lump-fishes range 
from the polar regions to Cape Hatteras, and are clumsy 
and shapeless, covered with tubercles. Their pectoral 
