92 MESSES. NOEMAN AND STEBBING ON THE 



the epistoma carries an acute spine, as does each segment of the peraeon, except the 

 last, which, in the same position, carries a large and stout process (i. l), nearly as 

 thick as the basos of a peraeopod, and two or three times as long as the ventral spines — 

 the male organ. 



Pleon with the epimera prolonged into acute processes, which are directed at first 

 outwards, and ultimately backwards ; these as well as the spines of the peraeon are 

 perfectly glabrous, and free from ciliation ; beneath, each of the first five segments 

 bears an acute spine ; the sixth segment is very long, almost equalling the rest of the 

 pleon, smooth, extremely truncate, but a little exserted in the middle. 



Antennae unusually long; the upper with the joints of the peduncle bearing nearly 

 the same proportion to each other as usual ; the first very long, cylindrical, but 

 slightly angular, glabrous; filament of twenty-four articulations. Scale of lower 

 antennae (i. a.i) very narrow and linear, its marginal setae few and distant, only twelve 

 in all. 



Mandibles with a greatly developed palp (i. m). 



The first gnathopods (i. L and I. gn 1 ) have the basos oblong, stout, and strong; the 

 meros is triangular, embracing within the base of the triangle the apex of the trian- 

 gular carpus, wbich about equals the basos in length, and only has three distant cilia 

 on the front margin; hand with the thumb projected laterally, so that its margin is 

 scarcely more advanced than the base of the finger; near the base of the thumb is a 

 projecting semicircular process, which is centrally hollowed, containing, as it were, a 

 small pocket ; a long, narrow, acute, conical process near the base of the impinging 

 margin ; beyond this the margin is crenated ; on one side this crenated margin is 

 furnished with a close, regular series of short, stiff, spatulate hairs (i. gn 1 !*), on the 

 other with a series of minute, flattened, jagged-edged, upright, microscopic teeth, one 

 such tooth occupying each crenation ; the finger is well arched, close to its base are 

 two rounded tubercles, and the rest of the inner margin is slightly crenately waved, 

 each sinus thus formed carrying a short, stumpy, spine-like tooth. 



Second gnathopods (i. l and I. gn 2 ) of weaker structure than usual, the pectinated spines 

 of the more distal joints assuming almost the form of stout cilia, while the cilia on the 

 other hand are so stout as almost to become spines ; basos with a tooth near its origin ; 

 ischium very short ; meros with a row of cilia passing obliquely along the side, and 

 terminating distally above, three or four setae also at the distal front corner ; wrist 

 longer than either meros or hand, its margins furnished with numerous greatly 

 developed cilia (20 on hinder, 15 on front margin), the front margin also bears two 

 slender spines, one near its centre, the other terminal, the distal side of these spines 

 is pectinated ; hand bearing cilia and spines of similar structure and size to those of 

 the wrist, of the former there are eleven on the hinder and six on the front margin, 

 together with four spines ; finger with two minute cilia on the outer and three denticles 

 on the inner margin. 



