50 T. V. HODGSON. 



it seems to resemble Jseropnix Koehler more closely than auy other, though the structure 

 of the set.-ond aatcumi and the uropuda should exclude it from the Janiridae as at 

 [)resent detiued. 



ArSTKONANUS GLACIALIS. 



(Plate VIII., fig. 3.) 

 Specific characters : — 



Cephiilosome broad, ratlior poiiit«l anteriorly. 



Second nntenuu, second joint produced externally as n flattened Made. 



Urosoiue with ten recurved teeth in front of the prelcriuinal uropoda. 



This is the most diminutive species iu tlic whole collection, and is of ovoid form. 



The cephalosome is large, with the lateral projections which carry the eyes 

 scarcely as broad as the first segment of the mesosome. The ocular projections are 

 very stout though not very long, their angles arc rounded, and the eyes, which are 

 red in colour, are quite small. Anteriorly the cephalo.some is arched forwards in 

 rather a pointed manner, and its anterior border is flattened. In length it is equal 

 to that of the first two segments of the mesosome. 



Of the mesosome the first two segments are subequal in length, the first is 

 curved forwards, the second is the widest, and, with the third, straight ; the remainder 

 progressively decrease in length and iu width, all of them being more or less curved 

 in a backward direction. The epimera, not separable from the body, arc almost the 

 full length of their respective segments, with rounded angles, and a distinct space 

 between each segment; there is no " waist" between the fourth and fifth segments. 



The metasome comprises only a single plate, the urosome. This is slightly 

 wider than the last segment of the mesosome and attached to it along half its width. 

 The external margins, as far as the insertion of the small uropoda, arc rounded and 

 armed with ten fiat curved teeth, which increase in size as far as these appendages ; 

 between the uropoda there projects a rounded lobe. 



The uropoda are short, single-jointed stumps, setose at the extremity. 



The first antenna is .short, and has a peduncle of two short joints and a flagellum 

 of five. 



The sccoml antenna has a peduncle of five joints ; of these the first is .small, 

 the second is large and mucli dilated externally, the third is short, the fourth twice 

 as long, and the fifth rather more than the length of the two preceding. The 

 fiagellum only contains about seven joints, and is scarcely twice as long as the last 

 joint of the peduncle. 



The mouth organs cannot be detected without di.ssection, and this has not been 

 done as there is but a .single specimen. 



The first of the percipoda is stout and a little shorter than the others. The basis 

 and isrliium are two stout joints, the latter not so long as the former, but details 

 cannot br seen without reiiiov.il from the Itmly. The merus is .short and enlarged 

 dorsally in a roiiiide<l niaiiiier, overreaeliing the base of the earjuis. The ear[)us is 



