202 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



as long, the caudal edge evenly curved, the setiferous tubercules 

 small and set back from the edge. 



Sternites smooth and glabrous, sternal area of metazonites raised 

 between legs hito a platform higher than level of prozonites, seg- 

 ments 8-10 each with a distinct cruciform impression, segments 

 11-16 with a large transverse knob between the second legpair. 

 Interzonal furrow broad and well defined on sides, curving in front 

 of spiracles, and reduced to a narrow suture across sternal area. 

 Spiracular opening large and reniform, its edges low and rounded. 

 Pleural areas finely granular, those of midbody segments swollen and 

 more tuberculate just above the legs. Caudal edge of metazonites 

 margined down the sides. Prozonites smooth and polished ventrally. 



Legs massive, the coxae without distal armature, prefemora with 

 short but acute distal spines and a characteristic knob on the dorsal 

 side. Femora robust, about twice as long as thick and little longer 

 than the other leg joints. Tarsal claw long and slightly curved, with 

 several very fine parallel ridges on the dorsal side. Legs, especially 

 anterior pairs, covered on the ventral sides with very thick pubes- 

 cence, the dorsal surfaces almost glabrous. Sternites of anterior 

 segments without modification except for very low knobs between 

 the 4th legpair. 



Gonopod aperture broadly transverse, about twice as wide as long, 

 with a raised margin in front of each coxite and caudally bounded by 

 the elevated sternal area between the 7th legpair. 



Coxae of gonopods heavy and subyclindrical, with short coxal 

 apodemes. Coxal apophysis small and distally indented. Telo- 

 podite about same length as coxa, its prefemoral division 60 percent 

 of length, and densely setose, prefemoral process rather long and 

 slender, evenly curved instead of medially geniculate. Tibiotarsus 

 slender and laminate, the leading edge finely fimbriate or serrate 

 distally. Secondary tibiotarsus slender, nearl}^ straight, a little longer 

 than primary, its subterminal process normally smaller than the tip, 

 and oblique to it, both distally divergent. 



Variation : The few specimens that have been available for study 

 afford practicallj^ nothing tangible in the way of variation. The 

 total length ranges from 53 to 62 mm. in three intact specimens. In 

 general the gonopods are remarkably alike in all three males, except 

 for what is apparently individual variation affecting the end of the 

 secondary tibiotarsus. As shown in figure 9, one of the prongs tends 

 to be longer than the other, but the type specimen of P. simulans 

 departs slightly in that the prongs are more approximate in size and 

 length. Aside from this, the remainder of the gonopod and the rest 

 of the animal is so similar to the other specimens of crassicutis that 

 simulans can scarcely be maintained as a distinct entity. The speci- 



