PENEOPSIS DIOMEDEZ. 187 
The legs are of moderate length for this family; they increase in length 
in successive order from the first pair to the last. 
The abdominal appendages are very long. Their proportions will be best 
understood by reference to the figure. 
The exopods of the second maxillipeds are very small, — not longer than 
the short ischial segments of these limbs. Upon the appendages behind 
these, the exopods are reduced to the merest rudiments, to be detected only 
by the use of a lens. In some specimens, indeed, the exopods of the pos- 
terior appendages are altogether wanting. 
The branchial formula is as follows : — 
Somites Wie —yWAasE 10:@ 
OK i di oct Sony 
Pleurobranchie 0 0 1 il il i 1 1G 
Arthrobranchie  1* 2 2 2 2 2 2 OSes 
Podobranchize 0 i 0 0 0 0 0 (== al 
Epipods 1 1 1 i 1 1 1 = (7) 
20 + (7) 
Length (female) 215 mm.3 carapace, 101 mm.; rostrum, 42 mm. ; anten- 
nal scale, 33 mm.; telson, 35 mm. 
Station 3353. 695 fathoms. 2 fem. 
“ douse: doo © 1 male. 
fs 3384. 458 * 3 fem. 
Ks 3395= 1020" << 3 fem. 
ce gate) Olle < 3 males, 1 fem. 
a S0908 oun < 1 male, 1 fem. 
I have assigned this species to the genus Peneopsis after some hesitation. 
Peneopsis, 2 MS. name of A. Milne Edwards’s adopted by Spence Bate, has 
never been properly characterized. According to Bate, it was separated 
from Peneus chiefly on account of the length of the antennular flagella, 
which surpass the carapace in length. I have examined with some care a 
specimen in this Museum from the “ Blake” collection, labelled “ Peneopsis 
oculuris” by A. Milne Edwards. In this specimen the cervical sulcus is 
deeply imprinted upon the surface of the carapace, but the posterior oblique 
portion of the conspicuous groove which runs from the cervical groove to 
the hinder part of the carapace in P. diomedew is obsolete. There is a 
very minute supra-orbital spine on the anterior margin of the carapace, 
a strong antennal spine at the lower limit of the orbit, a small spine (hepatic ?) 
* Very minute, but functional. 
