72 



the 4'*' joint. In the larger specimen the external maxillipeds reach almost to the tip of the antennal 

 scales, in the other to the distal fifth of their length ; last joint twice as long as penultimate. 



The i" pair of peraeopods (Fig. ij h) reach to somewhat beyond the middle of the 

 antennal scales; merus about 4-times as long as wide, the margins parallel to a little beyond 

 the middle, from where it narrows towards the distal end. Carpus a little more than half as 

 long as the merus, 4,6-times as long as thick; chela one-third longer tlian carpus, fingers 

 nearly one-fourth the length of the chela. 



Second legs (Fig. 17/) hardly longer than those of the i^' pair. Merus nearly as long 

 as in the 1^' pair, but 4Y2-times as long as wide, presenting for the rest the same form. 

 Carpus '/i,| shorter than merus, slender, 9-times as long as thick in the middle; chela Y- shorter 

 than carpus, fingers almost one-third the length of the chela. 



Merus of 3'^'^ or 4"^ legs (Fig. 17/) 7-times as long as wide, narrowing from the middle 

 toward the distal end, with 7 spines near and along the lower margin, while there are also 

 a few spines on the ischium. Carpus a little more than one-third the merus, 6-times as long as 

 thick; propodus 2Y3-times as long as the carpus, slender, 20-times as long as wide in the middle, 

 dactylus one-third the length of the propodus. 



Legs of the last pair reaching almost to the distal end of the antennal scales. Merus 

 just as long as in the preceding pair, but lo-times as long as wide and with only 3 spines 

 near the lower margin. Carpus "/h the length of the merus, propodus nearly 3-times as long 

 as the carpus, about 25-times as long as wide in the middle, dactylus very short, rudimentary, 

 almost hidden by a plume of setae. 



The pleopods of the 2'^^ somite are provided only with one stylet in both specimens, 

 which are therefore probably females. 



Family Nem.'\toc.\rcinii).\e. 



This family is represented only by the genus Nematocarcinus A. M.-Edw., Dr. Calm.\n 

 having proved already in 1896 that the species of the genus Stochasmus Bate is a true 

 Nematocarcinus. This remarkable genus was first discovered by the expedition of the "Blake" 

 in the Caribbean Sea, where Neviat. cursor, described in 1881 by A. Milnf.-Edw.^kds, proved 

 to be common at a depth of 500 fathoms and a second, certainly different form, Xemat. efisifer 

 (S. I. Smith) from off the East coast of the United States was made known in 1882. In the 

 Report on the Challenger Macrura, however, no less than 1 5 new species of Nematocarcinus 

 are described, chiefly characterized by the length of the rostrum and its denticulation, but the 

 author himself considered these characters already as untrustworthy, for, when describing Nemat. 

 proxiinatus at p. 808 of his work, a species differing from Neiimt. longirostris only in the 

 length of the rostrum and in the number of teeth upon it, especially on the lower margin, 

 Spence B.\te writes: "although for the sake of the convenience of classification 1 call them by 

 different specific names, I cannot help feeling that they are mere variable forms of one deep-sea 

 species". Some of these Challenger species now bear apparently such a close resemblance to 



