410 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [06] 



terizes the genus wholly on the branchiae, places it next to Aristeus, and 

 refers to it two species, each based on a single injured specimen; but as 

 our species is closely allied to Aristeus and agrees with Hepomadus in 

 the number and arrangement of the branchiae, it seems probable that 

 it belongs to Bate's genus. 



Male. — The carapax, the rostrum excepted, is of nearly the same form 

 as in Aristeus f tridens, but is a little more slender, the dorsal part of the 

 cervical suture is more conspicuous, and there is a well-developed hepatic 

 spine in addition to the two spines of the anterior margin. lu front of 

 the cervical suture the dorsum is carinated and projects forward in a 

 laterally compressed, regularly tapered, acute, and somewhat upturned 

 rostrum about half as long as the rest of the carapax, its dorsal edge 

 armed with two teeth ne^ir the middle and one just back of the base iu 

 the dorsal crest of the carapax proper, and the lower edge unarmed but 

 fringed with a series of long hairs. The eye-stalks and eyes are about 

 a fourth as long as the carapax, exclusive of the rostrum, and very nearly 

 as in Aristeus f tridens, except the prominences on the inner edges of the 

 stalks are larger, though not very much larger than in very young speci- 

 mens of the Aristeus. The eyes are minutely faceted and black pig- 

 mented. 



The peduncles of the antennula; reach nearly to the tips of the antennal 

 scales : the body of the proximal segment is about half the entire length, 

 but the spiniform lateral process does not reach the extremity of the 

 segment itself, which, however, is armed with a slender spine just out- 

 side the base of the second segment ; the second segment is about twice 

 as long as the distal. The flagella are imperfect. The second segment 

 of the peduncle of the antenna is armed with a stout spiniform curved 

 process just inside the base of the scale, as in Aristeus f tridens. The 

 antennal scale is about half as long as the carapax, including the ros- 

 trum, about three eighths as broad as long, and in form and texture 

 like that of Aristeus f tridens. 



The oral appendages are very similar to those of Aristeus f tridens., al- 

 though they show good distinctive characters. The molar areas of the 

 mandibles are larger and the triangular ventral angles of the crowns less 

 acute; the proximal segment of the palpus is somewhat shorter, and the . 

 expansion of the inner edge of the distal segment is a little nearer the 

 base. The distal lobe of the protognath of the first maxilla is much 

 narrower, so that the mesial edge is comparatively short. The second 

 maxilla differs scarcely at all, except in having the distal lobe of the 

 protognath a little narrower. The endopod of the maxilliped is appar- 

 ently composed of four segments, though the first articulation is rather 

 obscure and possibly the result of accident: the proximal segment is 

 much less than half the entire length, but is proportionately about as 

 long as in the Aristeus f ; the second and third segments are subequal in 

 length, but the second is narrower than the third and alone reaches be- 

 yond the tip of the protopod; the terminal segment is only about half 



