No. I.] A NEW PERIPATUS FROM MEXICO. 5 



Peripatus trinidadensis Sedgw. Trinidad. 28-32 



juliforinis Gilding. St. Vincent. 33 



edwardsii Sedgw. Venezuela. 29-34 



quitensis Schmarda. Quito. 36 



torquatus Kennel. Trinidad. 41-42 



It will be seen from this list, in which we have a gradu- 

 ated series of forms with legs varying from 14 to 42 pairs, that 

 the Mexican Peripatus has the lowest number of legs of any 

 American species with the exception of P. chiliensis} 



In the structure of its legs P. eisenii resembles the other 

 neo-tropical species. All the feet have four spiny creeping 

 pads, except the last two pairs, which have only three (Fig. 5). 

 The most proximal pad on the antepenultimate pair is very 

 small, so that this pair forms a transition between the feet 

 in front with four pads and the posterior feet with three. 

 According to Sedgwick, only the last pair of feet has three 

 spinous creeping pads in P. edwardsii. 



The opening of the nephridium on the fourth and fifth pairs 

 of legs in P. eisenii differs from that observed in other Ameri- 

 can species. The position of this opening is shown in Fig. 7. 

 The second pad from the base of the appendage is broken in 

 two, — a short posterior and a much longer anterior piece, — 

 and between them lies the papilla with the nephridial orifice. 

 In P. edivardsii the second spinous creeping pad is entire, 

 though somewhat narrowed in the middle; and the nephridial 

 papilla lies between it and the most proximal pad in the middle 

 line of the appendage, according to Sedgwick (PL XVII, Fig. 

 11). In the old-world species figured by Sedgwick {P. balfouri, 

 PI. XVII, Fig. 9, and P. novae zealandiae, PI. XIX, Fig. 21) 

 the nephridial papilla lies in the middle of the proximal pad, 

 which corresponds to the second pad from the base of the 

 appendage in P. eisenii and other new-world species. 



The position of the nephridial papilla in the middle longitu- 

 dinal line of the appendage, as represented by Sedgwick for P. 

 edwardsii, will not hold good for at least one other American 

 species, viz., P. trinidadensis. In the specimens of this species 



' The number of pairs of legs in this species has not been satisfactorily 

 reported. See Sedgwick, p. 197. 



