EPIZOA. 



131 



arc appended, and the abdomen, wherein the viscera are lodged, 

 is obvious. 



The rude and imperfect limbs that we have seen in the Lerneans 

 are visibly more perfect in their entire construction ; and in the fe- 

 male the posterior pair of these appendages is converted into a most 

 singular instrument of attachment, by which it fixes itself to the 

 gums of the fish. The hinder pair of extremities alluded to (Jig. 



53, &, b) are, in fact, enormously developed; they curve forward after 

 their origin from the posterior part of the trunk, and are so much 

 extended that they project considerably beyond the head of the 

 creature, where, becoming considerably attenuated, the two are 

 joined together by a kind of suture, and support, upon the point 

 where they are united, a cup-shaped organ whereby the creature 

 fixes itself. This singular instrument, represented upon an enlarged 

 scale &tjig. 54, 1, is of cartilaginous hardness, and resembles a little 

 bowl, the inside of which is studded with sharp teeth, and calcu- 

 lated not only to act as a powerful sucker, but, from the hooks 

 within its cavity, it is capable of taking a most tenacious hold 

 upon the lining membrane of the mouth. 



The other members (Jig. 53, o) are much less developed, but 

 are nevertheless so constructed as to assist materially in fixing the 

 Epizoon ; they are represented upon a very enlarged scale in Jig. 



54, 2, where the outer pair (a, a) are seen to exhibit in the transverse 

 lines indented upon their surface the first indication of articulated 

 members ; and their extremities, armed with minute hooks, evidently 

 form powerful agents for prehension. Internal to these are two 

 other jointed organs, still more feeble in their construction, the 

 ends of which (6, 6), being armed with three spines, will assist 

 in effecting the same object. 



(171.) The Figm 54 . 



mouth itself (Jig. 

 54, 2, c) is formed 

 upon similar prin- 

 ciples, the exter- 

 nal orifice being 

 surrounded with a 

 circle of minute 

 recurved spines 

 well calculated to 

 ensure its firm ap- 

 plication to the 



