124 



STALK-EYED CRUSTACEA. 



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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 



15. Of the two longitudinal ridges on the 



thus arranged : 9 (or 10) • — 3 — 

 infero-latcral 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 is obsolete on the sixth somite^ obsolescent on the fifth, and toothed only on 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 pleuras 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 XXXIIL, 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, 14,5 mm., dactylus, 

 22 mm.). 



Station 3380. 899 fathoms, 1 fem. 



This species somewhat resembles P. !ce?ns (Bate), P. validits (A. M. 

 Edw.), and P. dehilis (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(orl0) — 3-™15inplaceof8 



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 

 pleurse are subacute instead of being broadly rounded, etc. The difl^erences 

 between the present species and P. Imvis and P. dcUlis will be readily seen 



* The carapace is too broad by 2.3 mm. in the figure on Plate XXXTT. 



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