124 STALK-EYED CRUSTACEA. 
el 
anterior branchial lobe ; the orbital notch is narrow, and armed with a spine 
at its internal angle, and with another at its external angle. A spinule on 
anterior end of the opththalmic lobe and another at the outer anterior angle 
of the basal joint of the antennule. The marginal spines of the carapace are 
thus arranged: 9 (or 10) —3—15. Of the two longitudinal ridges on the 
infero-lateral wall of the carapace, the upper one is visible only in front of the 
cervical groove, the lower one is denticulated. The dorsal abdominal carina 
is obsolete on the sixth somite, obsolescent on the fifth, and toothed only on 
the first, second, and third; a shallow groove runs outward and backward 
from the dorsal carina to the point of articulation with the succeeding somite 
on the second, third, fourth, and fifth somites; a low, triangular tubercle 
at base of telson; telson tapering to a slender and acute tip; anterior 
abdominal pleurze rounded, gradually becoming acute as one passes back- 
ward to the sixth. The ischium of the cheliped is unarmed ; the merus is 
furnished with spines on the anterior edge, and is very minutely serrate on 
the posterior edge, which terminates distally in a long curved spine; the 
carpus is long and slender, and is equipped with a prominent sharp spine 
at the distal end of the outer margin; the basal portion of the propodite is 
spinulose along the upper margin, more minutely so on the lower margin. 
The fingers are spineless. 
The posterior thoracic limbs in the unique female specimen end in a 
small but perfect chela (Plate XX XIII., Fig. 2”). 
Length, 99.5 mm.; length of carapace, 45.3 mm.; greatest width of cara- 
pace, 38.5 mm.;* length of cheliped, 118 mm. (ischium, 19 mm., merus, 
33 mm., carpus, 22 mm., basal part of propodite, 14.56 mm., dactylus, 
22 mm.). 
Station 3380. 899 fathoms. 1 fem. 
This species somewhat resembles P. levis (Bate), P. validus (A. M. 
Edw.), and P. debilis (Smith). Compared with the type of P. validus the 
carapace of this species is broader anteriorly, there is but one spine at the 
external orbital angle in place of two, the formula for the lateral spines is 
9 (or 10) — 3— 15 in place of 8 — 4 — 30, the dorsal surface of the carapace 
is thickly beset with granules instead of being sparsely spinulose, the sub- 
marginal line is evident instead of being obsolete, the posterior abdominal 
pleure are subacute instead of being broadly rounded, ete. The differences 
between the present species and P. levis and P. debilis will be readily seen 
* The carapace is too broad by 2.3 mm. in the figure on Plate XXXII. 
