MUSEUM OF COMPARATIVE ZOOLOGY. 215 
Aristzus occidentalis, sp. nov. 
Similar to A. antennatus (Risso) of the Mediterranean Sea. By comparison 
with Duvernoy’s figures of A. antennatus it appears that the Pacific species 
has a longer, more strongly upturned rostrum, and that it differs furthermore 
in having the sixth abdominal segment carinated and toothed, and in having 
much longer abdominal appendages. As in A. antennatus, there is no epipod 
on either the last or the next to the last pair of legs. 
Length, 158 mm. ; rostrum, 49 mm. carapace, including rostrum, 85 mm. 
Station 3403. 384 fathoms. 1 male. 
Se S4LO2) Zalo 2 females. 
Hemipeneus triton, sp. nov 
This species, like H. spinidorsalis Bate, is remarkable for the long, curved 
thorn on the dorsal side of the third abdominal segment. It differs from 
H. spinidorsalis in having a much shorter rostrum, and longer, more flattened 
outer antennulary flagella. The rostrum is shorter than in any previously 
described species, being much shorter than the eyestalks ; it is furnished with 
from two to four teeth above. The sixth abdominal somite is longer than in 
H. spinidorsalis. Another difference between the two species affects the inner 
branch of the second abdominal appendages of the male; in both species this 
branch is triple; in H. spinidorsalis the anterior piece is a horny plate, concave 
within and furnished with sete on its distal border; the middle piece has the 
form of a long triangular tooth, shorter than the anterior plate ; the posterior 
piece is a longer multiarticulate flagellum, homologous with the inner branch 
of the following pairs of appendages. In JH. triton, the middle tooth-like 
process is developed into a broad plate which exceeds in length the anterior 
plate. 
Length, 127 mm.; carapace, 44.5 mm. ; rostrum, 6 mm. 
Station 3360. 1672 fathoms. 1 female. 
TS OVAg moos se 1 male, 5 females. 
se . Sa8L.) 1772 ‘i 3 males, 1 female. 
Benthesicymus tanneri, sp. nov. 
In this species the carina on the fifth and sixth abdominal segments termi- 
nates posteriorly in a small acute tooth, whereas in B. altus Bate these segments 
are devoid of teeth, the posterior margin rising to form a peculiar transverse 
ridge. JB. brasiliensis Bate differs from B. tanneri in having the earapace 
higher, with more convex infero-lateral borders, the third, fourth, and fifth 
abdominal segments toothed, the sixth toothless, and in the absence of the 
tooth or tubercle on the sternum between the abdominal appendages of the 
