G-ENEEA UEOTHOE AND UEOTHOIDES. 11 



amounting to generic difference, it might be necessary to revive Costa's name Egidia for 

 the European species ; but it is not very probable that any such necessity will arise. 



Ueothoe pulchella (Costa). (Plate IV. A.) 



1853. Egidia pulchella, Costa, Ricerche su' Crostacei Amfipodi del Regno di Napoli, Rend. d. Soc. 



r. Borbon. Acad. d. Sci. n. ser. 1853. 

 1857. „ „ Costa, Ricerche sui Crostacei Amfipodi del Regno di Napoli, Mem. d. R. 



Accad. d. Sci. di Napoli, vol. i. p. 190, tav. iv. fig. 3, a-g. 

 1876. Urothoe pulchella, Boeck, De Skand. og Ai'kt. Ampli. p. 325. 

 1885. Egidia pulchella, Carus, Prodromus Fauuis Mediterranete, pai's ii. p. 419. 

 1888. Uj-othoe pulchella, Stebbiag, 'Challenger'' Amphipoda, p. 297. 



Rostrum little developed, lower front corners of the head fully rounded ; third 

 pleon-segment with the postero-lateral angles not acute. 



Eyes reniform, except in the smaller stages, seemingly never very large. 



Upi^er antennm. First joint thicker but by no means longer than the second, each 

 having two lines of setae on the surface ; third joint shorter than the first, and much 

 more slender, nearly as long as the five- or six-jointed flagellum ; secondary flagellum 

 three- to four-jointed, longer than half the principal. 



Lower antennae. In the male specimen examined the fourth joint of the peduncle had 

 twenty-one spines in the outer row, five in the inner, and several small setfe ; the fifth 

 joint had a row of five spines near the outer margin, and eight long serrate setae near 

 the inner; the flagellum consisted of twenty-three joints, and was more than twice as 

 long as the peduncle. There being no brush of hairs on the fourth joint of the 

 peduncle, and there being spines but no calceoli on the fifth joint, this specimen may 

 not represent the fully adult male. In the female from Naples the fourth joint has 

 twenty-one spines in one row, two in the other, about a dozen long setae along one 

 margin, and seven at one corner ; the fifth joint shorter than the fourth, with a row of 

 eleven spines, ten long setae near the convex border, and six at the opposite distal 

 corner; the flagellum scarcely as long as the fifth joint of the peduncle, the first joint 

 carrying three rather slender spines, and the second six long set« and three shorter 

 ones ; the second joint is about one third the length of the first, its two apical 

 setae long. 



The triturating organs have on the confronting margins each twelve or fourteen stout 

 spines toothed on two edges, the series being continued along the distal border by six- 

 and-twenty slender serrulate spines or setae. 



Mandibles. The cutting-plate forming a strong blunt tooth ; the secondary plate 

 small, on the left mandible denticulate, on the right more slender, strap-like, slightly 

 bifid; the molar tubercle powerful; the second joint of the palp carrying nine setae, 

 three or four of which are very small; the third joint about as long as the second, 

 nearly acute at the apex, carrying eleven spines, four or five at the apex seta-like. 



c2 



