^4 Aimals of the South African Museum. 



occurs, although in its place a groove is often found such as that 

 described by Sedgwick for P. capensis. In some sections cut 

 transversely to the axis of a leg of P. ccq^ensis this groove was of 

 considerable depth and resembled that which would be produced if 

 the coxal organ in fig. 23 were removed and only the echinate 

 portion of the invaginated ectoderm were left. It is quite possible 

 that traces of a modified epithelium may sometimes be found at the 

 base of this groove in some forms, representing the rudiments of a 

 coxal organ. I have not, however, sufficiently investigated this 

 point. 



The function of the coxal organs is as yet unknown. They do not 

 appear to be of the nature of a gland, nor of use in conjunction 

 with sexual functions, as they are equally well developed in both 

 sexes. 



6. The crural glands. 



The crural glands of Opisthopatus possess some peculiar characters 

 apparently not yet noticed in other forms, although it seems 

 probable that similar structures occur in Peripatus, as will be 

 shown further on. 



Unlike the ordinary crural glands of Peripatopsis these glands are 

 very large and have, moreover, hitherto not been found in the female. 

 They occur in the male in the 6th to 13th pairs" of legs inclusive, 

 and may be easily seen when the animal is dissected under water. 

 Each gland forms a long tubular pouch, ending blindly at its inner 

 end, but passing over at the other end into a short duct, which opens 

 externally at the apex of a large retractile papilla, situated on the 

 ventral surface of the leg (fig. 26). The tubular pouch becomes 

 somewhat attenuated towards its blind end and is thickest nearer 

 the duct. It lies for by far the greater portion of its length within the 

 lateral sinus of the body, and may be directed forwards or backwards 

 more or less parallel to the nerve cord, which runs below it ; or it 

 may even be doubled back upon itself after running for a little 

 distance in the one or other direction. The irregular arrangement 

 of these tubes is well shown in fig. 15, in which they are drawn as 

 they appeared in the dissected preparation. Those in the hinder 

 part of the body reach scarcely beyond the bases of an adjoining 

 pair of legs, but in the middle and anterior parts they are much 



* This was certainly the case in two drowned males from Richmond, one of 

 which was dissected and then sectioned, and m a male from Dunbrody, which 

 was sectioned. In the remaining males, also, the external openings of these 

 glands were never observed on the first 5 or last 3 pairs of legs. 



