BOPYRUS SQUILLARUM. 219 



(Oniscus sq.). GOODSIR, in 



Ann. Nat. Hist. xi. p. 75, pi. 



7. MILNE EDWARDS, Crust. 



iii. p. 282. WHITE, Cat. Brit. 



Crust. (Brit. Mus.) p. 82. 



Pop. Hist. Brit. Crust, p. 256. 

 Monoculus Crangorum. FABRICIUS, Ent. Syst. Suppl. p. 



306. Boso, Hist. Crust, ii. 



216 (Bopyrus cr.). 

 Insecte qui s'attacM a la brevette. FOUGEROUX DE BONDAROY, Mem. 



Acad. Sc. 1772, p. 29, t. 1. 

 (Var. ?) Bopyrus Palcemonis. Risso, Crust, de Nice, p. 148. 



LAMARCK, Op. Cit. p. 165. 



DESMAREST, Crust, p. 326. 



THIS species has long been known in consequence of 

 its occurrence, during the summer months, beneath the 

 carapace of the common edible prawn, the presence of 

 the female causing a large tumour, of nearly half an 

 inch in diameter, on the side where the parasite affixes 

 itself. The female, in the ordinary condition, is flat- 

 tened and broadly ovate in form, and the minute male is 

 generally to be found fixed amongst the respiratory 

 plates on the underside of the tail of the female. The 

 male closely resembles one of the Idotece in miniature, 

 having the body elongate and narrow, with rounded, 

 flattened lobes at the sides of the segments of the body, 

 and with the tail of a reversed, triangular form, rounded 

 at the tip, with the six segments only indicated by five 

 incisions on each side, being confluent on the disc. The 

 antennae are very short, and resemble those of the 

 female, and the legs are also very short, although strong 

 and ch elate. 



The female is broadly ovate, but having the pleon 

 somewhat narrower than the pereion, flattened and 

 curved either to the right or left,* according to the side 



* This curvature is occasioned by the unequal pressure from the carapace 

 of the prawn. 



