186 C. Spence Bate on the Pencerdea. 
on the gastric region. Petasma folded so as to resemble two 
tridents, one on each side. 
Length 3 inches (male). 
Taken among the Celebes Islands in about 600 fathoms of 
water. 
Haliporus obliquirostris, n. sp. 
Rostrum elevated from the base obliquely upwards, armed 
with five teeth, and two larger ones on the gastric region. 
Telson sharp, as long as the plates of the rhipidura, and 
armed with two immovable teeth, one on each side. 
Length.about 3 inches (female). 
Taken off Kermadec Island. 
I should have considered these to be the females of ZH. 
neptunus, but for the separation of their habitats by so great 
a distance—no female being found with the former, and no 
male with the latter. ; 
Genus HEMIPENAUS, n. g. 
Rostrum horizontal, shorter, or, at all events, not longer, 
than the peduncle of the first pair of antennee. Ophthalmopod 
single-jointed, furnished with a small tubercle. First pair of 
antenne with the flagella unequal, one exceedingly short and 
implanted near the base of the third joint, the other very 
long and situated at the extremity. Branchial arrangement 
as follows :— 
Pleurobranchia ............ oo Ded), di laea se 
Arthrobranchi#@..........0. OE neaieea eye Gy = 72 
Podobranchia..........e0+- 1 als ee S 
Mastibranchia .........00. UEP Uys ie Thad ae) 
htktmn o mei 
2 otis) 
Hemipencus spinidorsalis, n. sp. 
Rostrum straight, sharp, styliform, armed with two teeth 
on the posterior and one on the gastric region, and one long 
spine-like tooth on the dorsal surface of the third somite of 
the pleon directed backwards. Appendages long and slender. 
Length about 3 inches. 
Taken in the South Atlantic, near the island of Tristan 
d’Acunha, in 1900 fathoms of water. 
Hemipenceus speciosus, i. sp. 
Rostrum anteriorly depressed, armed with three teeth on 
the upper surface, one of which is posterior to the frontal 
margin, the other two near together on the rostrum. Oph- 
thalmopod long and slender. Hye scarcely larger than the 
