ISOPODA. 235 



are very small and entirely inferior. The antennae consist of nine 

 joints, the last four composing the stem. On each side is a depressed 

 tubercle representing one of the intermediate antennae ; the interven- 

 ing space is raised. The branchiae arc vesicular, imbricated, and 

 covered by laminae *, 



LiGiA, Fah. 

 The stem of the lateral antennae composed of a great number of 

 small joints ; two very salient stylets divided at the end into two 

 branches, at the posterior extremity of the body. 



Ligia oceanica ; Oniscus oceanicus, L., Desmar., Consid., 

 XLIX, 3, 4, about an inch long, grey, with two large yellowish 

 spots on the back. The lateral antennae are less than half the 

 length of the body, and their stem consists of thirteen joints. 

 The stylets are as long as the tail. This animal is veiy common 

 on the coast of France, where it is seen climbing up the rocks, &c. 

 If an attempt be made to capture it, it quickly folds up its feet 

 and lets itself fall. 



In the Ligia italica, Fab., the lateral antennae are nearly as 



long as tlie body ; the sixth joint, or the stem, is divided into 



seventeen small ones. The stylets are much longer than the tail. 



Ligia muscoruin; Oniscus hijpnorum. Fab., Cuv., Journ. 



d'Hist. Nat. II, xxvi, 3, 4, 5 ; Oniscus agilis, Panz., Faun., Ins. 



Germ., Fascic. IX, xxiv. The lateral antennae shorter than the 



half of the body, and their stem composed of but ten small 



joints. The peduncle of the posterior stylets is furnished on the 



inner with a tooth and seta. 



In others, all terrestial, the lateral antennae consist at most of eight 



joints Avhich gradually diminish in- size towards the extremity, so that 



no one of them appears to be divided or compound. 



Here, the posterior appendages, or stylets, project beyond the last 

 segment. The body does not contract into a ball, or does it im- 

 perfectly. 



Philoscia, Lat. 

 The lateral antennae divided into eight parts and exposed at base ; 

 the four posterior appendages nearly equal. They are only found in 

 wet places f . 



Oniscus, Lin. 

 The true Onisci have also eight joints in their lateral antennae, 

 but their base is covered, and the two external appedages of the 

 extremity of the tail are much larger than the others. These animals 

 and those of the two following subgenera are vulgarly called Clous- 

 u-porte, and by syncope Cloporte, Porcelets de Saint-Antoine (a). 



* Ti/los armadiUo, Lat., fig, in the pi. d'Hist. Nat. of the great work on Egypt — 

 from the Mediterranean. 



f Oniscm sylvestris, Fab. ; Oniscus muscoruin, Ciiv., Journ. d'Hist. Nat. II, xxvi, 

 6, 8 ; Coqueb., Ill, Icon. Insect., Dec. I, vi, 12. 



{i^{a)These" Pigsof Sf. Anthony^' are American Wood-Lice — Boiled in milk they 

 still constitute a favourite remedy with numerous patients, and some few equally intelli- 

 gent practitioners, who attribute to them diuretic, absorbent, and aperient qualities. 

 That they may act as an emetic, I can readily admit. — Eng. Ed. 



