108 



ii. The antrorse spine iu which the carina of the 5th abdo- 

 minal tergnm culminates is of enormous size, its tip 

 overhanging the anterior border of the 4th tergum ... P. ceratus. 



2. The median carina of the carapace carries 3 spines (the penulti- 

 mate of which is double) between the rostral spines and the 

 cervical groove ... ... ... ... ... P. sculptus. 



90. JPolycheles phosphorus, Alcock. 



Pentacheles phosphorus, Alcock, Ann. Mag. Nat. Hist., March 1894, p. 240. 

 Illustrations of the Zoology of the Investigator, Crustacea, Plate VIII. Fig. 2. 



Carapace everywhere covered with a hairy tomentum, beneath which, except 

 for certain definitely placed spines, it is smooth : the antennnlar and antennal 

 peduncles, the edges of the last four pairs of thoracic legs and of the abdominal 

 pleura and tail-fan are setose. 



Carapace elongate-quadrate, depressed, its lateral borders parallel except 

 at the four corners, its length in the middle line about half a telson-length less 

 than that of the abdomen. Its frontal border is concave, with the orbital notches 

 deep and anned with a spine at their inner angle only. Its lateral borders are 

 armed with 15 or 10 spines, namely (rarely 7) + 3 (rarely 4) in front of the 

 cervical groove, and or 7 behind it. It is dorsally carinated in the middle 

 line from the anterior border, where the carina begins in a pair of juxtaposed 

 rostral spines, to the posterior border, where it splits and ends in a pair of 

 separated spines, which are the only spines on that border. Besides these spines 

 at either end, the carina carries in front of the cervical groove 4 spines the 

 penultimate of which is double, and behind the cervical groove 2 double spines. 

 On either side of the carapace the following spines are found : one on the 

 eyestalk, near its frontal end; 3 in an oblique row, behind the orbital notch; 

 one at the bifurcation of the cervical groove, and a pair at the end of the short 

 anterior branch of the groove ; a longitudinal row of spines parallel with the 

 posterior half of the lateral border; and some spines flanking the cardiaco- 

 branchial groove. The two obliquely longitudinal ridges of the sidewalls of the 

 carapace are also spinose. 



All the abdominal terga (including the true tergal element at the base of 

 the telson) are longitudinally carinated in the middle line. The carina? of the 

 first 4 terga culminate anteriorly each in an overhanging antrorse spine, that 

 of the 5th tergum ends abruptly, and that of the Gth tergum is double and 

 granular. At either end of the anterior border of the exposed surface of the 

 1st abdominal somite are two spines. 



Antennular scale a little larger than the antennal scale, its length being 

 about two-sevenths that of the carapace : at the outer angle of the basal joint 

 of the antennular peduncle is a single spinule. The narrow antennal scale 

 reaches to the end of the antennal peduncle. 



