186 
ACANTHOPTERYGII. — LABRID^. 
grinding away the whole calcareous surface ; hut j 
to the powerful jaws and teeth of the Lahridce I 
this is an easy task ; it is soon reduced to a pulp, 
and deposited in the stomachs of these fishes, j| 
where the nutritive matter is digested, and the | 
stony residue rejected. Some of the genera have [| 
the power of protruding the mouth, and some l| 
(as the genus Epihulus) can impart a see-saw | 
motion to the maxillary bones, analogous to that | 
peculiar action of the jaws in the RodenfAa, where- ji 
by they are enabled to gnaw away the hardest I 
substances on which they feed, and probably here | 
answering a similar end. I 
The beauty of these fishes is their only recom- ! 
mendation to man; their flesh is, for the most 
part, soft, and in no estimation as food. | 
We may consider the Lahridce as constituting 
three sub-families, distinguished by the following 
characters. 
1 . Labrina. In the typical group, the lips are 
very thick and fleshy ; they are double, one lip 
adhering immediately to the jaw-bones, the other 
to the sub-orbitals. The teeth in the jaws are 
conical, those in the pharynx cylindrical, arranged 
like a pavement ; the upper ones with two large 
plates, the under with one only, which fits to the 
others. The cutting teeth are sharp, simple, and 
distinct, those in front are the largest. The gills 
are thickly set, with five rays. The ventrals and I 
pectorals are small. About three hundred species j 
are enumerated as belonging to this group, which i 
includes all the Lahridce, thirteen in number, 
found on the British coasts. 
2. Chromidina. In many of their characters 
the members of this group resemble those of the 
