IDOTEA PARALLELA. 



ISOPODA. 



NORMALIA. 



391 



IDOTEIDJR. 



IDOTEA PARALLELA. 



Specific character. NaiTow, subcylindric, with the sides of the pereion 

 parallel ; eyes placed at the base of slightly elevated anterior lateral angles 

 of the cephalon ; outer antennae not one-fourth of the length of the animal, 

 with a very short two or three-jointed flagellum. Pleon rounded at the ex- 

 tremity, which is subobliquely truncate, with the margin elevated. First 

 pair of legs larger than the succeeding. 



Length, one-fourth to one-half of an inch. 



Idotea chelipes. Costa, Faun. d. Regno d. NapoH. Crust, pi. 11, f. 2. Hope, 

 Cat. Crust, p. 26 (but not of Fabricius, Mant. Ins. i, 

 241. Ent. Syst. ii. 506, nor of Latr. Hist. N. Ins. et 

 Crust, vi. 372). 



This new British species will not enter into any of Prof. 

 Milne Edwards' divisions of the genus, founded on the 

 structure of the basal segments of the tail, as our species 

 possesses three distinct although very short joints, 

 followed by a fourth joint, only indicated at the sides. 



