1382 THE VOYAGE OF H.M.S. CHALLENGER. 



apieally acute, the distal margin being in this and the other pairs pectinate on the under 

 surface ; the outer ramus a little shorter and broader than the inner, its outer margin having 

 three pronounced teeth, the inner edge having a ciliated and pectinate emargination 

 a little way below the base, the rest of the edge being microscopically pectinate almost 

 down to the acute apex ; the inner ramus has its inner margin smooth, and the outer 

 margin strongly pectinate, a ciliated emargination near the base facing that of the other 

 ramus ; the peduncles of the second pair are scarcely longer than the rami, which are as 

 large as in the first pair, the outer ramus with four teeth on its outer margin, the inner 

 edge finely pectinate, with a slight unciliated emargination near the base, the inner 

 ramus with the upper part of the outer edge faintly emarginate with a definite 

 pectination, which becomes almost imperceptible on the lower part ; the peduncles of the 

 third pair longer and broader than those of the first, the rami also similar to those of 

 the first pair, but much shorter, with two teeth only on the outer margin of the outer 

 ramus, and the inner ramus rather broader than the outer. 



Telson. — The length scarcely ecpial to the breadth, forming three-quarters of a circle, 

 about a third of the length of the peduncles of the last uropods. 



Length, in the position figured, and in a straight fine from the front of the head 

 to the extremity of the uropods, less than a fifth of an inch. 



Locality.— Station 200, October 23, 1874; off Sibago, Philippines; lat. 6° 47' N., 

 long. 122° 28' E. ; daytime, 80 fathoms ; surface temperature, 85° "5. The specimen 

 described, a male. 



Hyperia luzoni, n. sp. (PI. CLXVI., A.). 



Head deeper than long ; first two segments of the peraeon dorsally coalesced ; the 

 first three segments of the pleon almost scmared at the postero-lateral angles. 



Upper Antennas. — The first joint of the peduncle longer than broad, the second joint 

 very short, and the third still shorter ; the first joint of the flagellum tapering, nearly 

 as long as the peduncle, showing in the interior the preparation for the yet undeveloped 

 brush, at the apex carrying a few filaments; the remaining joints twenty-five in 

 number, not linear. 



Lower Antennas rather shorter than the upper. The third (first free) joint of the 

 peduncle longer than the fourth and shorter than the fifth ; the flagellum of twenty-four 

 short joints, the first the longest, showing preparation within for subdivision into three 

 joints. 



Mandibles with rather elongate trunk, the teeth of the molar tubercle not very much 

 crowded together, the first joint of the palp elongate, shorter than the second, which 

 curves outwards forming an angle with the first, while the scarcely longer, acutely tipped 

 third joint is directed inwards so as to form another angle with the second. 



