CIRRIPEDES. 77 



extremely analogous : for a more detailed description of 

 these members consult the explanation of Plate IX. The tail 

 which is usually bent up under the belly is extremely short, 

 composed of two joints, and terminates in four seta?, and is 

 employed to assist in progression and in changing the posi- 

 tion from a state of repose. The greatest peculiarity however 

 in the structure of this animal is the eyes, which although 

 constantly shielded by the valves of the shell, are peduncu- 

 lated ! as in the Crab and Lobster, and placed anteriorly 

 at the sides of the body. 



Any Naturalist acquainted with the Crustacea, on reading 

 this short description will readily assent to what has been 

 advanced as to the very extraordinary and anomalous cha- 

 racter of this little animal, and to the dislocations it seems 

 calculated to produce in ourClassifications : but for its pair of 

 pedunculated Eyes it would find place as a new Genus of the 

 bivalve Monoculi (Ostracoda) ; its members approximate 

 it to Argulus on the one hand and to Cyclops on the other. 

 Genera which are widely separated ; while its Eyes shew 

 its relationship to the Decapoda (Crabs, Lobsters &;c.) ; 

 reflecting upon all these circumstances, and others viz. 

 their great abundance during the early part of spring 

 alone, and their presenting no variation indicative of a 

 difference of sex, induced a belief that they were the larva 

 or disguised state of some Crustaceous animal, or (as it 

 had been previously ascertained that the Cirripedes were 

 Crustacea) that they were the males of these, not being- 

 disposed to believe that the two sexes were united in the 

 same individual; in favour of this idea too, it may be observed 

 that the males of many Crustacea are remarkably less in 

 size and different in aspect, as in the Caligi and Bopyri, 

 and also that in some they are rarely met with, and only 

 at a particular season, one impregnation serving for all the 

 broods thrown off in the course of the animal's life, as 

 in Daphnia ; to which may be added that all the Barna- 

 cles examined by comparative anatomists, have proved to 

 be of the female sex or were at least furnished with ovaria. 



K 



