479 



the form described below, 2 exotic species have been recorded from the 

 soutlierii liemisphere b}- the Rev. Mr. Stebbing, viz., T. cmlarctka and 

 T. Jcerguelenia. 



'J. Tritaeta gibbosa (Sp. Bate). 



(PI. 168, fig. 2). 



Ali/Iuf: i/ibhoms, Rp. Bate, Cat. Ainpli- Brit. Mus. p. 1;?7, I'l. XX VI, tig. 3. 



•Syii. : Dexamiue bvevitarsis, Gnibo. 

 > Lauipra gibbosa, Boeck. 



Body of female much inflated in its anterior part, nearly depressed, 

 and having- the back broadly vaulted; that of male .somewhat more compressed. 

 Fir.st segment of urosome with a rather large gibbous projection at the end 

 dorsally. Cephalon not nearly attaining the lengtli of the first 2 segments 

 of mesosome combined, anterior corners rounded, with a very slight angular 

 projection in front. The 2 anterior pairs of coxal plates oval quadrangular 

 in form, with the anterior corner angularly produced; the 2 succeeding ones 

 much broader and expanded distally to 2 angular lappets; 5th pair not very 

 large, with the anterior lobe much deeper than the posterior, both being 

 obtusely rounded at the tip. Last pair of epimeral plates of metasorae 

 produced at the lateral corners to a compai'atively short acute point. Eyes 

 rather large, and rounded oval in form, somewhat widening below, pigment 

 reddish brown, with a whitish coating Superior antennae considerably 

 exceeding half the length of the body, 1st joint of the peduncle much sliorter 

 than the 2nd; flagellum twice the length of the peduncle, and composed of 

 about 18 articulations carrying slender bristles. Inferior antennse in female 

 very little shorter than the superior, last joint of the peduncle not attaining 

 the lengtli of the penultimate one, flagellum nearly twice the length of tiie 

 peduncle ; those in male, as usual, much more elongated and having the 

 penultimate and antepenultimate joints of the peduncle densely clothed with 

 sensory hairs, flagellum very slender, filiform. Anterior gnathopoda with the 

 basal joint fully as long as the remaining part of the leg, carpus widening 

 distally, and forming below a short setiferous lobe, propodos about the length 

 of the 2 preceding joints combined, and rather expanded, rounded oval in 

 form, with 3 transverse rows of bristles on the upper edge and another 

 running across the propodos inside, at some distance from the palm, the 

 latter about the length of the hind margin, and defined below by a very 

 slio-ht angle. Posterior gnathopoda somewhat more elongated than the 



