ONYCHOPHORA OF WEST AUSTRALIA. 



381 



The Nephridia of the 'ith and 5th pairs of leys (PI. I. fig. 2, 

 Nepb.'). These nephrirlia differ from the others firstly in the 

 increased length of the tube betAveeu the distal collecting vesicle 

 and the opening on the leg. This is due to the fact that the 

 renal aperture is situated near the extremity of the appendage. 

 The vesicle presents the same structure as before. From the col- 

 lecting vesicle a long, tubular portion extends posteriorly within 

 the lateral compartment of the body. This section presents the 

 same type of wall as the corresponding section of the other 

 nephridia. Having reached somewhere about the second suc- 

 ceeding pair of legs the tube turns on itself and runs forward, 

 the two limbs being in close contact. The wall still presents the 

 large flattened cells. This section passes into the ciliated duct, 

 which is particularly well marked in these nephridia, and opens 

 into the cffilomic chamber, which lies close to the distal collecting 

 vesicle. 



The Reproductive Organs. 



A somewhat detailed description of the reproductive oi'gans of 

 the West Australian Peripatoides is rendered necessary owing to 

 the fact that Bouvier's specimens of the northern variety were 

 not sufticient to allow of a complete and accurate account of the 

 anatomy. This applies in particular to the female, in which con- 

 nection Bouvier states (3) "L'appareil genital femelle ne presente 

 rien de particulier, si ce iiest Vatropjhie complete, on a pen, pres 

 complete, des receptacles semiiiauxy The rece})ta.culum seminis 

 is, however, well developed. The ex[)la,nation of the mistake 

 probably lies entirely in the state of preservation of the few 

 specimens available. VV^e have had the good fortune to obtain 

 many specimens and to preserve them in many ways. 



The Male Reproductive Or<ja)is consist fi'st of the two testes, 

 which lie fairly far forwards entangled amongst the diverticula of 

 the slime glands (see PI. I. fig. 3, Tes.) and dorsal or lateral to 

 the alimentary canal. These organs are tubulai and from the wall 

 cells are cut off which are apparently the spermatocytes. These 

 do not develop into spermatozoa in the testes. Apparently the 

 development of spermatozoa takes place in the vesicida seminalis 

 (see Photomicrograph, PI. III. fig. 14). 



This feature is to my mind rather interesting ; yet it is one 

 which is never mentioned ni text-books. It was naturally 

 thought at first to be quite a new discovery. As a matter of fact 

 it was seen by Ga.ffron many years ago and figured in his work (8). 

 GafFi'on was struck also by the resemblance to the conditions in 

 the earthworm and actually writes: " Etwas aehnliches findet 

 sich bekanntlich beim Regenwurm, wo ja audi die eigentlichen 

 Hoden den ' Samenblasen ' gegeniiber sehr zuriicktreten und die 

 Weiterentwicklung deV Spermatozoen in letzteren stattfindet." 



Each testis opens into a seminal vesicle (PI. I. fig. 3, S.Y.), 

 one usually lying somewhat in front of the otliei- owing to the 



