REPORT ON THE CRUSTACEA MACRURA. 501 



still shorter than the second, and carries two subequal flagella. neither of which is 

 quite as long as the peduncle. In the male the outer branch is more robust and stronger 

 than the inner, while in the female they closely correspond in size and appearance. 



The second pair of antennae has the scaphocerite broad and short, with the margins 

 subparallel, and reaching but very little beyond the extremity of the ultimate joint of the 

 peduncle of the first pair ; the external margin terminates in a sharp tooth, beyond the 

 extremity of which the internal or foliaceous portion extends a little, and is fringed with 

 long cilia. The fiagellum is slender and about half the length of the animal. 



The mandible (<r/) is slightly curved, cylindrical, and terminates at the molar process 

 (<l\ d") in two sharp, fork-like points, supplemented with a cutting tooth. The organ is 

 not implanted deeply in the surrounding structure by an apophysis, but attached to 

 muscle tendons at the extremity. 



The first pair of gnathopoda (li) is short and subpecliform ; it is five-jointed and scarcely 

 as long as the secondary ramus or basecphysis ; the whole organ is richly adorned with 

 long cilia. 



The second pair of gnathopoda (?) is four-jointed. The first joint or coxa is short ; the 

 second, which probably consists of the basis, ischium and meros united, is long, slightly 

 excavate on the inner side near the base, corresponding with the oral aperture, and on 

 the outer side supports an ecphysis scarcely half the length of the joint to which it is 

 attached ; the third joint is more slender than the preceding, and about one-third its 

 length ; the fifth is more slender than the third, and slightly longer. 



The first pair of pereiopoda (/>:) has the anterior margin of the palm (&') oblique, waved, 

 and separated from the short pollex by a deep notch, in which the extremity of the dactylos 

 rests when closed. The second pair of pereiopoda (/) scarcely reaches beyond the carpos of 

 the first, it is slender and terminates in a small chela, the fingers of which are gaping 

 and nearly as long as the propodos ; the carpos is uniarticulate, longer and more slender 

 than the propodos, while the meros is about the same length. The third pair of pereio- 

 poda (m) is long and slender, reaching considerably beyond the distal extremity of the 

 first, and beyond that of the second pair of gnathopoda or either fiagellum of the first 

 antennse ; the dactylos is styliform, long, slender, straight, cylindrical and pointed ; 

 the propodos is cylindrical, very little if at all longer than the dactylos, and scarcely 

 more robust ; the carpos is subequal in length to the propodos and slightly stouter ; the 

 meros and ischium are subequal in length, the latter being the more robust ; the basis is 

 short, and the coxa is long and tolerably large. There is no tooth nor rudiment of 

 one on the ventral surface of the somite between this pair of appendages. The fourth 

 and fifth pairs of pereiopoda are similar to each other. They are shorter and more 

 robust than either of the preceding, and terminate in a long, slightly curved, flattened 

 and pointed dactylos. Posterior to the coxa on the ventral surface of the last somite of 

 the pereion is a strong calcified plate. 



