MACRURA. SCHMITT. 369 



two loops, instead of one [as in P. latisulcatus and P. 

 japotiicus], between the posterior part of the post-ocular 

 ridge and the rostral crest; of the two loops that are 

 separated from one another, from the rostral crest and 

 the post-ocular ridge, by deep, though narrow sulci, the 

 inner is a little shorter than the outer." 



The rostrum in thirteen of the "Endeavour" 

 specimens of P. plebejus was armed, as in Hess's type, 

 with ten teeth above, and one below, while eleven others 

 were provided with a further or eleventh tooth above. 



The males are much like those of P. latisulcatus, 

 though of relatively frailer build. The petasma, of which 

 Pesta gives a sketch in lateral view, is not unlike the 

 figure given for Kishinouye for P. latisulcatus, the pro- 

 tuberances at the end of the inner "blade" of the petasma 

 being well developed though small, and not overhanging 

 the anterior margin of the outer "blade" to any extent. 

 Often, these protuberances or knobs at the anterior ends 

 of the inner blades of the petasma are very small or 

 obsolescent, no doubt due to the relative stage of 

 maturity attained by the specimen in question. 



The thelycum as de Man has it, "has a somewhat 

 different form from that of P. latisulcatus. The two 

 lateral plates or lobes come in contact with each other 

 at the median line, as in P. latisulcatus,, the distal third 

 or fourth excepted, but their form is semi-elliptical and 

 their lateral margins that are slightly curved run nearly 

 parallel, whereas in P. latisulcatus, they distinctly 

 diverge backward. The lobes show about the form 

 figured by Bate except that in this figure the lobes are 

 not in contact. In P. latisulcatus the two lobes are there- 

 fore broader at their base than in the middle, whereas 

 in the Australian species they are a little broader in the 

 middle than posteriorly. The median protuberance differs 

 likewise. Both in P. latisulcatus and in P. plebejus it 

 consists of a posterior part, bounded at either side by a 

 small ridge and an anterior portion that terminates 

 anteriorly in two horns. In the female of P. latisulcatus 

 this posterior part is shorter than the anterior, and 

 the two horns are comparatively large and separated 

 by a broad interspace. In P. plebejus, however, the 

 posterior part is larger than the anterior, and, the two 

 horns are very small and almost contiguous. This pro- 

 tuberance has been quite wrongly figured by SPEXCE 



