112 THE VOYAGE OF H.M.S. CHALLENGER. 



46' W. (Stations 349-352) ; in lat 26° 21' N., long. 33° 37' W. (Station 353) : in lat. 

 13° 50' S., long. 151° 49' E. (Station 181). 



The list of synonyms which I have assigned to this species might, I feel sure, lie very 

 considerably enlarged, some of the forms described by various authors being, as I think, 

 founded upon stages of development of Corycceus varius. 



2. Corycceus pellucidus, 1 Dana, (PI. LII. figs. 15-19). 



Corycceus pellucidus, Dana, Crust. U. S. Expl. Exped. (1852), p. 1224, pi. lxxxvi. tig. 6. 

 ,, rostratus, Claus, Die frei lebenden Copepoden (1863), p. 157, pi. xxviii. fig. 5. 



Length, 1 -26th of an inch ("97 mm.). Body moderately elongated; abdomen short 

 and composed of one joint only (fig. 15) ; first body-segment produced between the foot- 

 jaws and the first pair of swimming feet into l broad conical prominence ; third thoracic 

 segment produced into broadly triangular lateral processes reaching to the middle of the 

 abdomen, and completely hiding the fourth segment. Anterior antennae (fig. 16) six- 

 jointed ; posterior not very powerfully prehensile (fig. 17), basal joint long and bearing- 

 two long, plumose, spine-like setae, second joint narrow, and possessing no marginal teeth ; 

 terminal claw short and weak. Posterior foot-jaw (fig. 18) small, and bearing on the 

 inner margin of the hand a small plumose hair. Caudal stylets (fig. 19) much shorter 

 than the abdomen, about four or five times as long as broad, the terminal setae short. 

 All the specimens seen were females, and many of them had attached to the abdomen 

 bundles of spermatic tubes, very large for the size of the animal, and tapering to each 

 extremity. These are shown in fig. 19. 



A few specimens only of this species occurred in the following gatherings: — South 

 Pacific, December 5, 1875 ; in lat, 36° 44' S., long. 46° 16' W. (Station 325) : in lat. 9° 

 43' S., long. 13° 51' W. (Station 342) ; and at St. Vincent, Cape Verde Islands. 



The following interesting remarks of Dr. v. Willemoes Suhm refer to a species 

 which appears to be identical with Corycceus pellucidus, the only important differences 

 between our specimens and v. Willemoes Suhm's figures being found in the pectoral 

 process — which in " megalops" is much curved and rather slender, in pellucidus straight 

 and obtusely conical — and the eyes, which in pellucidus, are considerably larger ; 

 this latter point, however, need not be much insisted on, as v. Willemoes Suhm especially 

 remarks upon the "extraordinary size" of the eyes. The figures, which are valuable as 

 having been taken from the living animal, are reproduced in the woodcut, Dr. v. 

 Willemoes Suhm's note is as follows : — 



Corycceus megalops. — On our way from Teiiariffe to St. Thomas, in lat. 23° 10' N., and long. 38° 

 42' W., 1 found, among the animals which were got by the towing-net on the surface, a little blue 

 Copepod, which especially attracted my attention by the large size of its eyes. The peculiar loDg 

 1 En the talile of species (p. !>) this is given as Corycceus rostratus. 



