ONYCTIOPHORA OF WEST AUSTRALIA. 379 



Wibhout <lenyiug their occasional existence in tlie female 

 P. capensis, I may say that I have failed to find them present, 

 and I doubt, on a jJ^'iori grounds, if they normally occur in the 

 female." 



In tlie paper (11) to which Willey refers the following state- 

 ment is made : " I have examined several legs of P. cajKiisis, 

 both of males and females, and have found a crural gland in 

 every one except the first pair of legs." 



A careful search through sections of female Peripatoides of 

 Western Australia has shown that crural glands do occasionally 

 occur in the female. They are not always present, however,'and 

 when found there is no regularity as to the legs containing them. 

 In any case they ai^e not highly developed, although they have 

 the same vesicle with the same pink-staining homogeneous con- 

 tents found in the male. 



The Nephridia. 



A very careful study of the nephridia of Westei'n Australian 

 Peripatoides has been made, and well-preserved sections have eluci- 

 dated many points. It will be perhaps desirable to describe their 

 structure in detail, especially since some features, the presence of 

 cilia for example, are now made known for the first time. Mention 

 of cilia occurs in all general descriptions of Peripatus, but only 

 to the efi^ect that they are found in the generative ducts. The 

 cilia discovered in the nephridia of Perijxctoides are remarkably 

 well developed and of great length, reminding ore more of flagella. 



The nephridia, with the exception of those of tlie 4th and 5tli 

 pairs of legs, open on the ventral surface at the junction of 

 each leg and the body. Those of the 4th and 5th pairs of legs 

 are quite difi'erent from the others. They open on a special 

 papilla situated on the ventral surface of the respective legs (see 

 PI. I. fig. 2, Neph.'). It is rathei^ striking that with variations 

 in the anatomy of the Onychophora,, and in particular with 

 considerable variations in the number of legs, there should be such 

 a constancy in regard to the position of these special nephridia. 

 They are of almost exactly the same form in the West Australian 

 Peripatoides as in Peripatus capensis, and similar enlarged 

 nephridia occur in other species. 



Nephridia are found in all the pairs of legs without exception 

 in the West Australian Peripatoides. 



Structure of a typical Nephridiitm.— The aperture, which, except 

 in the case of the 4th and 5th nephridia, is unmarked by any 

 papilla, appears as a little crevice in the epidermis. This leads 

 into a short tube of minute diameter. This duct passes upwards 

 into the lateral compartment of the body and opens into a thin- 

 walled collecting vesicle (PI. lY. fig. li, Coll. Ves.). The cells 

 of the duct are small, cubical, or somewhat flattened, but the 

 vesicle is lined by a very delicate squamous epithelium of large 

 cells, the nuclei appearing distinctly some distance apart. The 

 vesicle might easily be mistaken for a split in sections were it not 



