GAMMARIDEA. 955 



are nearly four times as long as the head, have longish hairs below. 

 The setae of the ten posterior legs are few, and on the third or fourth 

 legs, are about half as long as the fourth or fifth joints; on the fifth 

 to seventh legs, half shorter. The hairs of the hands are as long as 

 the breadth of the hand. 



This species may possibly be the female of the G. tenellus. Yet 

 this seems improbable, since, in that species, the sixth pair of legs is 

 longer than the seventh, and the stylets of the last pair extend much 

 beyond the second. 



Gammarus quadrimanus. 



Gracilis, epimeris angustis. Antennae, lmce dimidii corporis longitudine, 

 basi paulo longiore quam flagellum, articulis primo secuncloque longis, 

 subcequis, fertio perbrevi, flagello pubescente, setis longioribus quam 

 articuli, vix divaricatis, appendice dimidio flagelli parce longiore. 

 Antennae 2do3 breviores, basi breviore quam basis lmarum, flagello 

 perbrevi. Pedes lmi parvidi, manu oblongd, infra hirsutd, basi 

 angustiore. Manus 2dce cequce, validissimce, subquadratce, apice trans- 

 versa, digito immobili spiniformi, acuto,palmd transversa, prominenter 

 %-dentatd, digito palmd vix longiore. Pedes 4 postici subcequi, 7 mis 

 parce brevioribus, articulis apice postico dense hirsutis, setis aliis bre- 

 vibus. 



Slender, epimerals narrow. Superior antennas half as long as the 

 body, base a little longer than the flagellum, first and second joints 

 long, subequal, third very short, flagellum pubescent, setae longer 

 than joints, and hardly divaricate, appendage rather longer than 

 half the flagellum. Inferior pair shorter, base shorter than base of 

 superior pair, flagellum very short. First pair of feet quite small, 

 hand oblong, hirsute below, narrower at base. Hand of second pair 

 equal, very large, subquadrate, apex transverse, a spiniform acute 

 immoveable finger, palm three-dentate, teeth prominent, finger 

 hardly longer than palm. Two posterior pairs subequal, the seventh 

 a little the shorter; the joints at their posterior apices densely hir- 

 sute, other setae short. 



Plate 65, ^.g. 9 a, animal, enlarged; b, portion of flagellum of supe- 

 rior antennae ; c, extremity of anterior pair of feet, more enlarged ; c' 

 same, of size corresponding to fig. a; d, tarsus of leg of fourth pair 



