(J4 THE VOYAGE OF H.M.S. CHALLENGER. 



as the body, twenty- four-jointed, very sparingly provided with long setae. Posterior 

 antennae, mandibles, maxillae, foot-jaws, and swimming feet as in the preceding species. 

 Terminal spines of the swimming feet strongly serrated, very similar to those of JEuchceta 

 hessei. Fifth pair of feet of the male (fig. 17) elongated, that of the left side simple, 

 slender, not clawed ; on the right side ending in two very long, slender, opposable claws, 

 one of which is armed with a series of small marginal tooth-like tubercles, the other with 

 several larger angulated protuberances. The abdomen of the male is four-jointed, of 

 the female three-jointed, the first joint having a hook-like process on the dorsal surface. 

 Caudal segments very short, setae stout, subequal, about as long as the abdomen, and 

 densely plumose. 



Habitat.— Taken in the North Atlantic at night, near Station 353, May 7, 1876, 

 about lat. 27° N., long. 33° W. Though many specimens of Euchceta pulchra occurred 

 in this gathering, I have not seen it in any other, and this is, I think, the only 

 instance amongst the Challenger collections in which the night captures have yielded 

 any peculiar species. Amongst the Copepoda there does not, indeed, appear to be so 

 great a difference between nocturnal and diurnal species as there is amongst some other 

 tribes of pelagic Crustacea. 



4. Euchceta (?) philippii, n. sp. (PI. XXI. figs. 1-4). 



Female (J) — Length, 1 -4th of an inch (6 - 2 mm.). Cephalothorax robust, broad in 

 proportion to the length. Anterior antennae (fig. 2) about as long as the cephalothorax, 

 twenty-five-jointed, second joint much larger than the rest, which are not very unequal 

 in length, the whole limb profusely clothed with more or less adpressed hairs, those of 

 the last eight joints longer than the others. The chief terminal spines of the swimming 

 feet (fig. 3) are very coarsely serrated, having only about twelve serrations ; the larger of 

 the secondary spines unusually well developed, at least half as long as the principal spine, 

 and densely cdiated. There is a rudimentary fifth pair of feet (fig. 4), extremely small, 

 and composed of two obtuse, cylindrical branches. 



Habitat. — A very few specimens only were noticed amongst the captures from lat. 36° 

 44' S., long. 46° 16' W., depth 2650 fathoms (Station 325), and a few, probably referable to 

 the same species, from Station 288 (lat 40° 3' S., long 132° 58' W.). This species is only 

 provisionally assigned to the genus Euchceta. The mouth-organs — mandibles and foot- 

 jaws — are exactly those of the normal female Euchceta, but the presence of a fifth pair of 

 feet, though very small, is abnormal. If a male this specimen certainly cannot be rightly 

 referred to Euchceta, inasmuch as the mandibles, maxillae, and foot-jaws are fully 

 developed. The anterior antennae and the spines of the swimming feet present well- 

 marked specific characters, and are quite unlike those of any other species known to me. 



