12 



The abdomen differs from that of Stcreoni. phosphorus by the median carina of 

 the 4"' t e r g u m that does not culminate in an acute a n t r o r s e spine, but the 

 distal end of which is obtuse and rounded. For the rest, however, the abdomen 

 apparently fully agrees with the quoted figure of Stercom. pJwsphorus in the "Illustrations" and 

 with the description. The carinae of the three first terga culminate each in an 

 acute, overhanging, antrorse spine; those of the i*' and of the 2°^^ tergurn are 

 small, of the same size, that of the 3''^ is considerably larger. The carina of 

 the 5"^ terminates not at all in a tooth, but ends abruptly and presents, in a lateral view, 

 the same form as the carina on the 4"^ tergum of Polycheles gracilis (Challenger Macrura, PI. 

 XVI, Fig. 2). The carina of the 6"^ tergum is double, both edges are denticulate and 

 unite posteriorly. The carina at the base of the telson carries posteriorly two small teeth 

 behind one another, the anterior tooth a little larger than the other. Like in Stereom. phosphorus, 

 the anterior border of the smooth first somite carries at either end two small spines of equal 

 size. The terga of the 4 following somites are obliquely and very deeply cleft at either side 

 of the median carina, like in Stercom. phosphorus; these terga are, however, not smooth, but 

 somewhat uneven and tubercular, especially on the edges of the oblique grooves. The 

 tergum of the 6'^^ somite appears a little shorter in proportion to its breadth than in the figure 

 of Stercom. phosphorus : in the adult female from Stat. 316 this tergum is 7.5 mm. long in the 

 middle line, its width at the antero-lateral angles is 15.5 mm. At either side of the double carina 

 this tergum appears somewhat granular, like also near the antero-lateral angles. 



The pleura are strengthened each by a salient, curved, minutely granular midrib, shaped 

 as in Stereom. aurictilata (Challenger Macrura, PI. XV'I, fig. 4), and one observes some sharp 

 granules between this rib and their denticulate posterior margin; the much larger pleura 

 of the 2"^^ somite are also somewhat granular or tubercular on their anterior half and they 

 carry a small spine at their anterior end. The caudal fan resembles that of Stereom. phosphorus. 



Immediately in front of the two rostral teeth arises from the frontal wall of the carapace 

 ("metope" of Spence Bate) a slender, conical tooth directed upwards and slightly forwards; this 

 tooth reaches barely, however, to the level of the upper surface of the carapace. 



The antennules and the antennae fully agree with those of Stercom. phosphorus, except 

 that there are two spinules at the outer angle of the basal joint of the antennular peduncle; 

 the larger anterior spine is placed just near the arcuate acoustic sulcus on the upper surface, 

 the second is only half as long and placed immediately behind it. There is a compressed 

 tooth at the distal end of the inner border of the antepenultimate joint of the antennal peduncle 

 and a smaller spinule occurs at the distal end of the inner border of the penultimate and of 

 the last joint. The antennal scale reaches by its spiniform extremity as far forward as the antennal 

 peduncle, the antennular scale is a little longer and its spiniform extremity is turned upwards. 



The external maxillipeds reach as far forward as the penultimate joint of the anten- 

 nular peduncle. 



In the adult female the i*' pair of thoracic legs are just as long as the body, they 

 resemble those of Stereom. phosphorus. The upper margin of the merus carries 2 or 3 spines 

 in the middle of its upper margin, the lower margin is finely spinulose along its whole length 



