REPORT ON THE CRUSTACEA MACRURA. 607 



is connected with the basis near the basisal articulation ; the ischium is lono- but not so 

 long as the preceding joint, and is furnished with a series of rows of hairs on the 

 inner surface ; the meros, which forms the distal joint, is about half the leno-th of the 

 ischium and is longitudinally hollowed, or spoon-shaped, having the margins fringed 

 with hairs. 



The first two pairs of pereiopoda (k) are similar in form, chelate, short, and somewhat 

 feeble. The coxa carries a fasciculus of long hairs placed on a prominent tubercle, and 

 the slender rudiment of a mastigobranchial plate, fringed on the lower or convex 

 margin with long hairs ; the basis is short and carries no ecphysis ; the ischium and 

 meros are subequally long and overlap each other obliquely, the upper margins of both 

 being fringed with stout hairs, and the lower and outer surface with soft hairs ; the 

 carpos is short, lunate, and produced to an angle on the upper surface. The propodos is 

 subcylindrical, slightly curved, and has the anterior extremity lanceolate in form and 

 flattened on the inner side, and the margins fringed with long, finely ciliated hairs ; 

 it articulates near its centre with the lower angle of the carpos, and is produced nearly 

 as much behind the articulation as in front of it, and it also articulates with the 

 dactylos at the posterior extremity, the base of the dactylos being nearly as broad as 

 the diameter of the propodos. The dactylos is formed on the same plan and is placed 

 in an antagonistic position, so that these two joints together form a chela of a peculiar 

 and unusual form. The second pair resembles the first and is of similar proportions. 

 The third pair is simple and much larger than the preceding ; the coxa is as broad 

 as long, and supports a rudimentary mastigobranchia similar to the preceding, but 

 larger ; the basis is short, and the ischium and meros are fused together and very 

 greatly enlarged, being nearly as long as the carapace ; it is covered with coarse 

 tubercles that have much the appearance of pointed processes rubbed down by wear. 

 The carpos is curved on the upper surface and waved on the lower, being narrowest 

 near the meros ; near the centre of the inner and lower side is a prominent tooth 

 standing on a slight elevation ; the propodos is broadest at the carpal extremity, and 

 gradually narrows to the dactyloid articulation ; the dactylos is short and of smaller 

 diameter than the distal extremity of the propodos. The carpos and propodos are 

 covered with coarse teeth or pointed tubercles, smaller than the largest of those on the 

 meros, among which, particularly on the lower surface, are some short stiff hairs. The 

 fourth pair is much smaller than the third, but developed like it, and the fifth pair 

 also differs only in being smaller and in having no rudiment of a mastigobranchial 

 appendage. 



The first pair of pleopoda (PL CXIX. fig. l£>) is biramose, the branches being sub- 

 equal, are in the male short and deflected from each other ; the inner branch is rigid and 

 terminates in a blunt point, the outer side is fringed with a closely packed row of short, 

 reversely curved, hook -like spines, that are continuous to the base of the branch, while 



(ZOOL. CHALL. EXP. — PAKT LII. 1887.) Fff 88 



