ANCEUS. 181 
but the three posterior segments of the body are almost 
as compactly soldered into a mass as in the females, 
whilst the two large plates covering the mouth are fully 
developed. These small males must, we should presume, 
be subject to another moulting before arriving at the 
fully developed state of the male sex, unless, indeed, 
they are slightly developed specimens, such as are known 
to occur in most cornuted species of animals. The female 
is said to be parasitic in the young state, and to live in 
crevices of the rocks when full grown. We believe that 
this is the case also with the male, and that both males 
and females change their oral organs with the final or 
adult moulting. 
The following remarks which we make on the 
habits and structure of these animals are so much at 
variance with the common notions concerning crusta- 
ceous animals, so high in the class as those of this 
genus, that we think it but just to ourselves to say, 
that we have only arrived at them after close and 
numerous dissections, and a long consideration of the 
subject. 
The females live parasitically on fish, burying their 
heads almost to the eyes; and we repeat that we believe, 
that up to the same period the male does also; but with 
the adult moult the female quits the parasitic life for a 
new kind of existence. With the adult moult the male 
getsrid of the lanceolate oral appendages, and large, pro- 
jecting mandibles are developed. We have some reason 
to believe that the production of the great prehensile 
mandibles of the male may be produced after the animal 
has put on the adult form, since we have several speci- 
mens in which these appendages are membranous, and 
have not yet acquired their distinctive form. It may be, 
however, that our specimens represent those which, by 
