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 

 gets rid 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 





