Mr. W. Thompson on new species of British Crustacea. Ill 



tooth is placed at the distance of about one-fourth the length 

 from the extremity. The thicker filament of the internal antennae 

 is large, and more curved than in H. varians. 



Abdomen slender, not at all gibbous, much compressed. Last 

 joint of fourth leg jagged on the inner margin. Two long 

 slender spines at the base of the antennae. External antennae 

 nearly the length of the animal. Length If inch. 



Colour a lovely dark meadow green, with, whilst ahve, a 

 whitish band running down the carapace; one specimen only 

 out of thirty or forty differed, and that was of a flesh-colour. 

 Middle plate of the tail acute, with two pair of minute spines, 

 one pair on each margin. 



I took this species for the first time on the 4th of May. I 

 obtained others on the 30th of May, and caiTying ova on the 

 14th of June ; the ova appear of a yellowish colour, but as they 

 did not reach below the scales of the abdomen, I did not examine 

 them as I could wish. 



I obtained my specimens in four to six fathom water in a 

 weed bed, on a stony bottom, in Weymouth Bay. 



This species is exceedingly like Hippolyte varians ; it is, how- 

 ever, of a much loveher form and colour. Though larger, it is 

 far more slender than any of the genus. 



The main points of difference with H. varians are, that the 

 rostrum is more elongated, not so acute at the apex, has no spine 

 on the ridge, and has a minute spine very near the apex on the 

 under side, thus making three spines on the under side. The 

 spines on the carapace are much shorter. The carapace is less 

 gibbous. The scale of the external antennae is longer and nar- 

 nower, and the spine is nearer the extremity. The thick filament 

 of the internal antennae is stouter and more bent, and the animal 

 is larger. 



They are more difiicult to keep in confinement than many 

 others, and far less lively. 



Some I had spent the whole of their time clinging to the fronds 

 of a piece of Furcellaria fastigiata, Ipng the length of the frond, 

 and not across it ; and however often I distui'bed them, they in- 

 variably found their way back. 



I have named this species after Mr. Adam White, one of the 

 Assistants at the British Museum. 



I have just had some more specimens brought me, amongst 

 which I find one with the rostrum much turned up (fig. 1 b), — 

 quite as much so as in Palaiiwn varians; — two with the rostrum 

 cuiTcd very much downwards (fig. 1 c), giving them a most 

 extraordinary appearance ; these I consider provisionally, until I 

 obtain other specimens, as varieties of H. M hitei ; I propose to 

 name the first H. IVhitei (var. ensis), and the second H. Whitei 



