LEGS IN SEVEEAL SAMPLES 383 



segment, dilated in the middle and ending obtusely. The 

 first antennae are short, the second long, with the Hagellum 

 shorter than the peduncle. The mandibles are without 

 ' palp ; ' the maxillipeds have the two terminal joints of 

 the 'palp' very short. The third pair of limbs of the 

 perseon are the most robust, while the fourth pair are very 

 small, and the seventh not much larger. The uropods are 

 long, slender, simple, two-jointed. The type is the Nor- 

 wegian Macrostylis spinigera, from a specimen about a six- 

 teenth of an inch long. Macrostylis latifivns, Beddard, 

 from 2,050 fathoms in the North Pacific, is a fifth of an 

 inch long. Vana longiremis, Meinert, 1890, beyond doubt 

 agrees genericallj' and probably also specifically with the 

 type of Macrostylis. 



Ischnosoma, Sars, 1866, meaning ' a slender body,' is, 

 perhaps, the most singular-looking of this family. The 

 fourth and fifth segments of the peraeon are fused, and 

 combine to form a columnar centre to the animal. The 

 pleon is constricted at the base. There are no eyes. Tbe 

 mandibles have a large molar, but no ' palp.' The first 

 limbs of the peraeon are short and robust, the others slender 

 and long. The uropods have a single one-jointed branch. 

 The type is the Norwegian species, Isclinosuma bispinosum, 

 Sars. The same author has described an Arctic species, 

 Ischnosoma quadrispinnsum. Beddard adds Ischnosoma 

 spinosum (see Plate XIV.), from the Azores, Ischnosoma 

 bacillus, from 60° south latitude, Ischnosoma bacilloides, 

 from South America, and Ischnosoma Thomsoni, from 2,050 

 fathoms depth in the North Pacific. 



Family 2. — Munnopsidce. 



The animal has a bipartite appearance, the anterior 

 portion consisting of the head and first four segments of 

 the pereeon, the last three segments of the perteon and the 

 consolidated pleon forming the other. There are no eyes. 

 The first limbs of the peraeon are subprehensile and shorter 

 than the three following pairs of limbs, which are ambu- 

 latory and in general very elongate ; the next two or the 

 next three pairs are natatory, having some of the joints 



