374 CLASS CRUSTACEA. 



the following are terminated by two long digits ; the others 

 are in the form of membranaceous leaflets. Caligiis jjroduc- 

 tus, Mull. Entom. xxxi. 3, 4; Monoculus Salmoneus, Fab. 

 The last subgenus of this subdivision, that of 



Anthosoma, Leach, 



Approaches the preceding, as far as the existence of a siphon, 

 and that of the two filaments at the end of the tail ; but is re- 

 moved from it, as well as from those which precede it, by rea- 

 son of two of its antennae, carried forwards, in the form of small 

 nionodactylous claws, and of the last six feet, which are mem- 

 branaceous, joined inferiorly, and folded laterally on the post- 

 abdomen, so as to form a case to envelope it ; those of the 

 first and third pair are unguiculated ; the second are termi- 

 nated by two short and obtuse digits. Anthosoma Smithii, 

 Leach, Desm. Consid. 1.3; Caligus hnhricatus, Risso. 



In others the body is oval, without projecting appendages in 

 the manner of a tail, composed of filaments, or of appendages 

 in the form of lines, at its posterior extremity. A portion of 

 the upper teguments forms at first, and in front, a buckler, 

 not covering its anterior moiety, being more narrow, rounded, 

 and emarginated anteriorly, widened, and, as it were, bilobate 

 at the other end ; then come successively three other pieces, 

 or scales, rounded and emarginated posteriorly ; the second 

 of which, the smallest of all, is almost in the fonn of an in- 

 verted heart, and the last and largest is vaulted. The four 

 posterior feet are in the form of laminae, and united by pairs; 

 those of the first and third are unguiculated ; the second 

 have their extremities bifid. The siphon is apparent. The 

 eggs are covered by two oval pieces, contiguous, coriaceous, 

 placed under the abdomen, and exceeding it in length. 

 Such are the characters of the genus 



