DESCRIPTIONS OF GENERA AND SPECIES. 287 



short, deep, curved, swollen at their proximal ends, 

 then suddenly narrowed and tooth-like. 



The anus reaches the hind margin, but does not 

 project : there are three pairs of small hairs near its 

 posterior end, of which two are pectinated ; there is 

 also a pair of very small fine hairs between the rostrum 

 and the first epimera, and a similar pair between the 

 first and second epimera. 



Male is smaller than the female, and is widest 

 between the second and third COXBB ; thence it diminishes 

 in width to the posterior end ; which is rounded, not 

 excavated in the middle as in the female. The dorsal 

 surface is more arched than that of the female. The 

 hairs are practically similar to those of the female, 

 except in being rather larger. The legs, especially 

 the two posterior pairs, are thicker than those of the 

 female ; the two anterior pairs are about the same 

 length, but the posterior legs shorter than those of the 

 female, particularly in the tarsi of the fourth pair. 

 These tarsi, and those of the third pair, are very different 

 from those of the female. They are curved imvard, 

 and are evidently suited for holding the female ; on 

 their upper surface, in the median line, they have a 

 blade which increases in width towards the distal end 

 of the joint. Haller saw this, but described it as a 

 ridge which projected like a tooth beyond the end of the 

 joint; this is its appearance when seen from above, 

 because it is on edge, but when the leg is dissected off 

 and looked at from the side it is seen that the part is a 

 blade curving over the end of the joint and then 

 truncated (PL XIX, figs. 5, 6). The caroncle is 

 described and figured by Haller as simply wedge- 

 shaped ; this is undoubtedly its appearance when it is 

 lifted off the ground, or when it has been soaked in 

 fluid or reagents; the sides then collapse and hang 

 down, or fold over the median part ; but if the caroncle 

 be examined with an amplification of 300 to 500 dia- 

 meters when the creature is alive, and walking or 

 standing on the under- side of a thin cover-glass, a very 



