ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 287 



pairs wide in the middle but narrowed at the base, and mucronate at 

 the terminations ; the inner margins of the raini of the first pair, and 

 the inner margin of the outer ramus, and both margins of the inner 

 ramus of the last two pairs, are elegantly serrated. 



Hyperia oblivia, Kroyer, Gronlands Amphipoder, p. 298, pi. iv. fig. 19 (but not 

 H. oblivia, Bate & Westw. vol. ii. p. 16). Filaments of both antennae 

 consisting of only a single joint. First gnathopods with wrist and hand 

 subequal, the former spined posteriorly, not at all produced distally; 

 hand slightly tapering, palm serrate distally, finger two-thirds as long- 

 as hand. Second gnathopods with meros sheath-formed, tipped with 

 spine-like setae and overlapping carpus ; carpus greatly produced dis- 

 tally into a lobe which reaches nearly to the extremity of the hand ; 

 finger straight, two-thirds as long as hand. Pereiopoda, last three pair 

 much longer and more slender than in H. galba ; carpus and propodos 

 both very long, the latter the longer, both with small distant spines on 

 the hinder margin, and the whole hinder edge of the propodos micro- 

 scopically pectinate. Eami of all the uropods lanceolate (not widening 

 in the middle), gradually tapering to the end (not mucronate as in 

 If. galba) ; the general serrated character of the margins of the rami. 

 agrees with H. galba, except that the external margin of the inner 

 ramus of the second pair is not serrated. The male differs from the 

 female, as in the last two species, in having the antennae very long and 

 slender. 



A female from an Aurelia, and males taken living free in the towing- 

 net. It has also been sent to me by Mr. Edward from Banff; and 

 Mr. G. S. Brady has procured both sexes in some numbers off the mouth 

 of the Tees in the towing-net. 



Bate and Westwood's " H. oblivia" which has not the propodos of the 

 gnathopods at all produced, cannot be Kroyer's species nor that here 

 described*. Goes takes Kroyer's Lestrigonus exulans to be the male of 

 H. oblivia ; and as far as the description and figures go, it may be the 

 male either of that or of H. galba ; but the short pereiopoda of L. exulans 

 and L. Kinaliani of Bate will not agree with the male of H. oblivia. 

 Metoecus medusarum, Krb'yer, Gronlands Amphip. p. 288, pi. iii. fig. 15 (not 

 Hyperia medusarum. Bate, Cat. Amphip. Crust. Brit. Mus. p. 295). 

 Female antennae very short; filaments of both pair one-jointed. Both gna- 

 thopods nearly alike, short, distinctly chelate, and of peculiar structure ; 

 meros produced into a large sleeve-shaped process, postero-distally tipped 

 with setce, which fits round the basal portion of the carpus ; carpus 

 postero-distally produced into a large lobe, which extends as far as the 

 extremity of the propodos, with which and with the finger it forms a 

 regular chelate organ ; propodos slightly tapering from the base to the 

 extremity ; its inner margin, the inner margin of the small finger, and 

 the inner margin of the thumb-used lobe of the carpus all denticulately 

 serrated ; hand and wrist wholly free from hairs or spines. Pereiopods of 

 moderate length; carpus and propodos subequal, their inner margins 

 microscopically pectinate. All the uropods having the inner margin of 

 outer ramus, and both margins of inner ramus serrated. The male 

 differs from the female in having very long antennae. 



A female found in a Medusa in Shetland in 1867 ; and a male has 

 been sent to me by Mr. T. Edward from Banif. 



The Hyperia medusarum of Bate bears no resemblance to Kroyer's 

 * I would propose for it the name of H. gracilipes. 



