222 DE. C. CHILTON ON THE SUBTEEEANEAN 



rows of setae, each containing four or five, the lateral surface of the joint also hearing 

 two or three small tufts of seta? ; the fifth joint is as long as the fourth, hut rather more 

 slender, armed with setse in a similar way to the fourth, hut with more numerous tufts ; 

 the flagellum shorter than the fifth joint, consisting of five joints, of which the first is 

 the longest ; the articulations hetween the joints are ohlique, and each hears at the 

 extremity a row of four or five small setse, and there is another row of four or five rather 

 longer setae on the lower margin towards the extremity. 



The upper lip (fig. 5) is rather delicate, hroader than long, the extremity very slightly 

 emarginate and somewhat sparingly sujiplied with the usual incurving seta?. 



The mandibles (figs. 6, 7, 8, 9) closely resemhle in general shape those of Nipl/arfftis, 

 as descrihed hy Humbert and other authors. The palp is rather large in proportion 

 to the mandible itself; it has tlie first joint small, the margins without setae; the second 

 joint rather broad, especially in the middle, where it is strongly curved, the convex 

 margin hearing about six or seven long setee, which project almost at right angles to the 

 joint; the third joint about as long as the second, outer margin nearly straight and 

 without setae, inner margin bearing on the distal half a double row of long setoe, which 

 increase in length towards the distal end. The palp is the same in both mandibles. 



The outer cutting-edge is practically the same in both mandibles, and consists of five 

 teeth, the two largest of which are somewhat widely separated, the other three teeth are 

 smaller and subequal. In the right mandible (fig. 6) the secondary cutting-edge is very 

 similar to that of Niplmrgus imteanns, figured by Humbert, and resembles in shape an 

 open hand with the fingers close together ; the part corresponding to the thumb is denti- 

 culated throughout, while that corresponding to the fingers has the distal extremity 

 oblique and finely serrate. At the base of this secondary cutting-edge are two stout 

 spiniform setae denticulated similarly to the thumh, and follov.ing these is a stout plumose 

 seta (see fig. 7). 



The secondary cutting-edge of the right mandible usually has the form just described, 

 but it is evidently subject to some variation, for in one specimen, which otherwise 

 appeared quite normal, it had the form represented in fig. 8, which, it will be seen, 

 is very different from the usual form. Whether this was the result of accident or not I 

 cannot say, but it shows how careful one ought to be before laying much stress on the 

 form of these minute mouth-parts unless they are found to be constant by the examina- 

 tion of a large number of specimens. 



In the left mandible (fig. 9) the secondary cutting-edge resembles the outer cutting- 

 edge, and consists like it of five separate teeth ; at its base are stout denticulated sets 

 similar to those in the left mandible. It will be seen that this figure is inverted. 



The molar tubercle, which appears to be the same in both mandibles, is small and 

 presents no remarkable feature. 



The lower lip (fig. 10) is very delicate, broad; extremity of each outer lobe very 

 broadly rounded and covered Avitli fine setae ; inner lobes small and very delicate ; the 

 lateral backward processes are short and rather obtuse. 



l:\iGfirst maxilla (figs. 11, 12, 13) is very similar to that of Niphargiis puteanus. The 

 palp has the first joint short, its extremity oblique; the second joint slightly narrowing 



