REPORT ON THE CRUSTACEA MACRTJRA. 343 



our typical specimen, but the coxa in comparison with that of the preceding pair is 

 remarkable for its lar^e size. 



The first pair of pleopoda is single-branched, moderately long, and has a large mem- 

 branous curtain attached to the base of the first joint, which extends across the ventral 

 surface and is united in the median line to its fellow on the opposite side by a series of 

 cincinnuli. 



The second pair of pleopoda is biramose, the anterior ramus being shorter than the 

 posterior ; two small membranous leaf-like appendages are attached to the anterior 

 extremity of the peduncle. 



The third and following pairs of pleopoda are two-branched, the outer or posterior 

 branch being the longer. 



The sixth or ultimate pair has the branches subequal, slender, tapering, fringed with 

 tolerably long hairs, and twice as long as the telson. 



This interesting form is so closely allied in general structure to Benthesicymus, that 

 I hesitated to remove it from that genus. But the characteristic formation of the 

 second pair of gnathopoda, the large secondary eye-tubercle, the peculiar form of the 

 articulation of the third joint of the first pair of antennae, together with the structure of 

 the branchiae, compel me to place it in a separate genus. 



The specimens taken at Stations 232 and 235, near the southern shores of Japan, 

 were got in comparatively shallow water, the depths being 345 and 565 fathoms 

 respectively, or something less than from half to three-quarters of a mile from the surface. 



The specimens from these stations, most of which are females, are nearly twice as 

 long as the fully-developed male from Station 230 in the same locality, but where the 

 water is three miles deep, which was only 30 mm. long, about the length of most others 

 from similar depths. 



Gennadas intermedins, n. sp. (PL LVIII. fig. 3). 



External structure soft and membranous. Carapace anteriorly produced to a broad, 

 sharply-pointed rostrum that is not more than half the length of the ophthalmopoda. 

 Near the apex a thin carina arises which is dorsally elevated to a crest, that is armed 

 with a single tooth above the frontal margin, and by the rudiment of another still further 

 behind, but in advance of the gastric region. The rest of the animal corresponds in 

 general appearance with Gennadas parvus. 



The ophthalmopoda are nearly half the length of the peduncle of the first pair of 

 antennas, are obliquely compressed, support an ophthalmus which is not of greater 

 diameter, and bear on the inner side a prominent tooth-like process that reaches as far 

 as the base of the ophthalmus, and gradually tapers to a point which is furnished with 

 one small lens. 



