REPORT ON THE CRUSTACEA MACRURA. 259 



longitudinally grooved, fringed at the margins with fine cilia, amongst which one small 

 spine is visible on close inspection. 



Length — female 88 mm. (3"5 in.); male, 63 mm. (2 - 5 in.). 



Habitat— Station 188, September 10, 1874; lat. 9° 59' S., long. 139° 42' E.; 

 Arafura Sea, south of Papua ; depth, 28 fathoms ; bottom green mud. Six males and 

 one female. 



Station 190, September 12, 1874; lat. 8° 56' S., long. 136° 5' E.; Arafura Sea, south 

 of Papua; depth, 49 fathoms; bottom, green mud. Two males having nine teeth on 

 rostrum. Taken with one of the females of the preceding species. 



Off Yokohama, in from 5 to 20 fathoms. Three males and three females. 



On the 18th September 1874, near the Arrou Islands in the Arafura Sea, between 

 Stations 190 to 191, a male specimen was taken associated with Penaeus velutinus. 



Rostrum horizontal on the dorsal surface, where it is armed with several small 

 equidistant teeth. In the male they have a tendency to be fewer than in the female. 

 In some specimens of the former I have counted as few as six (but two from Station 

 190 have nine), and in the latter the number is very constantly eight, and in addition 

 there is one more distantly planted on the gastric region. The lower margin of the 

 rostrum is free from denticulations, but closely fringed with ciliated hairs; in the male 

 the lower margin is less curved in its ascent than in the female, and has consequently 

 a narrower and sharper appearance. There is a small carina that traverses the median 

 line to the posterior extremity of the carapace. It is lost on the first somite of the 

 pleon, but reappears in the shape of a small tubercle near the centre of the second 

 somite, after which it appears again on the third, whence it is continuous to the 

 posterior extremity of the sixth and is there produced to a small tooth. 



On the frontal margin of the carapace is a small orbital tooth and a tolerably strong 

 antennal one, and between them a longitudinal depression that appears to be connected 

 with the orbit ; it carries a well-formed hepatic tooth, which, unfortunately, has been 

 omitted by the lithographer in the figure. 



The ophthalmi are ovate and moderately large. The first pair of antennae has the 

 peduncle longer than the rostrum, and supports two flagella equal to the peduncle in 

 length ; the outer and inferior is the larger and in both sexes tapers gradually to the 

 extremity. The prosartema reaches to the extremity of the eye, but scarcely beyond 

 it, and the stylocerite does not reach to beyond half the length of the ophthalmopod. 

 The second pair of antennas has the scaphocerite extending beyond the rostrum, but not 

 quite as far as the extremity of the peduncle of the first pair, and the external distal 

 tooth extends nearly as far as the distal extremity of the scaphocerite. 



The first two pairs of pereiopoda carry on the basis a long and spiniform tooth. The 

 third pair in the female carries the external passage of the oviduct, projecting on a small 



