188 THE GENUS PEEtPATUS. 



In a male with 30 pairs of legs : 



Right side. — Legs 21 — 24 inclusive, each had one such tubercle ; legs 

 25 — 28 inclusive, each had two such tubercles; legs 29 and 30 were 

 without them. 

 Left side. — Leg 21 had oue tubercle ; leg 22 was without one ; legs 23 

 and 24 eacii had one ; legs 25 — 28 inclusive, each had two ; legs 29 

 and 30 were without them. 



In another male with 30 pairs of legs : 



Right side. — Leg 23 had one tubercle ; legs 24 — 28 inclusive, each had 



two ; legs 29 and 30 were without. 

 Left side. — Leg 22 had one ; legs 23 — 28 inclusive, each had two; legs 



29 and 30 were without them. 



When one papilla only is present it is the distal one. 



From these examples it is obvious that the arrangement of 

 these tubercles is different not only in the different individuals 

 but also on opposite sides of the same individual. The legs of 

 the last two pairs are always without them. Gaffron found 

 precisely the same irregularity in the arrangement, but in his 

 specimens they were symmetrical. In one with thirty pairs 

 of legs, the legs of the 22nd pair each had one, and those of 

 the 23rd to the 28th pair each had two tubercles. While in 

 another male with twenty-nine pairs, the legs of the 20th pair 

 had only one each, while the legs of the 21st to the 27th pair 

 each had two. The pits at the apices of these tubercles are, 

 according to Gaffron, the openings of glands corresponding to 

 the crural glands ofCapensis. 



The legs of the last pair are smaller than the penultimate, 

 and possess only two spinous pads. The legs of the penulti- 

 mate pair are without the nephridial opening, and the pedal 

 groove is inconspicuous as it is in the last pair. I could not 

 satisfy myself whether the legs of the last pair possessed a nephri- 

 dial opening ; but Gaffron states that they possess a nephridium. 



Gaffron (No. 35) describes a peculiar bean-shaped papilla, 

 placed in a pit of the integument on the dorsal surface of the 

 leg near the foot. Its surface is smooth, as is also the lining 

 of the pit in which it is placed. It is found in the Trinidad 

 species, and may very probably turn out to be characteristic 

 of the neotropical species. 



