REPORT ON THE CRUSTACEA MACRURA. 307 



of this genus rather than with Aristeus, especially in the rudimentary condition of the 

 pleurobranchise, and in having no mastigobranchia attached to the fourth pair of 

 pereiopoda. 



The outer branch of the tail-fan is long and narrow, about one-half longer than 

 the inner, which is about one-fourth longer than the telson. The outer margin 

 is strengthened by two parallel ridges that meet in a sharp tooth some distance from 

 the distal extremity. From near this tooth a rigid diaeresis obliquely traverses the plate. 



A fine specimen of a female, about 150 mm. long, measured from the frontal margin 

 to the extremity of the telson, was taken by the trawl about 130 miles north-east of the 

 Iverrnadec Islands, and three others were also trawled at a depth of nearly three-quarters 

 of a mile close to the same islands ; these were one adult female and two young animals, 

 one of which carries an antenna that is more than three times its length, and the smallest 

 specimeu appears to be an immature male. 



HemipensBus tomentosus, Spence Bate (PI. XLIX. figs. 2, 3 ; PI. L.). 



Aristeus tomentosus, Sp. B., loc. tit., p. 189. 



Body smooth, covered with a very short velvety pile. Rostrum equal in length to 

 the extremity of the shorter flagellum of the first pair of antennae; armed with three teeth, 

 of which the posterior is just behind the orbital margin of the carapace, the second in 

 advance of it, and the third near the middle of the rostrum. The dorsal carina is only just 

 indicated in the median line behind the posterior tooth, feebly repeated on the posterior 

 portion of the third somite of the pleon, and increases on each of the three posterior 

 somites, where it is produced to a small pointed tooth. 



The telson is pointed, dorsally flattened, with indications of a groove, and armed on 

 each side with three small spines. 



Habitat.— Station 177, August 18, 1874 ; kit, 16° 45' S., long. 168° 7' E., the New 

 Hebrides; depth, 130 fathoms; bottom, volcanic sand. One specimen ; female. 



Station 200, October 23, 1874; lat. 6° 47' N., long. 122° 28' E.; the Philippine 

 Islands ; depth, 250 fathoms ; bottom, green mud. Two females. 



Length (female), 125 mm. (5 in.). 



This species bears a general close resemblance to Hemipenseus semidentatus, but is 

 easdy distinguished by the slightly pilose character of the external surface, and by the 

 shortness of the rostrum, which is only half the length of the carapace. The teeth on the 

 rostral crest are further apart and not so large. There is not a very distinct ridge 

 traversing the upper margin of the branchial chamber, and the mid-branchial rib is 

 but feebly marked. The teeth on the frontal margin of the carapace correspond with 

 those of the typical species. 



