656 o:s THE urogexital organs of the kaxgaroo, 



Of one of the specimens described in tlie paper (P.Z.S., ISSl) 

 it is said that " there are no distinct longitudinal folds in the 

 urogenital chamber," while the condition of the other is not given. 

 In one only of all my specimens is there any difficulty in recog- 

 nising ridges similar and similarly situated to what have been 

 described in other species ; the chief difference being that they 

 are shorter and as a rule not so conspicuous as in the Red and 

 the Wallaroo. In average specimens the ridges are about f in. 

 long, ^ in. high, iV in. broad. In the specimen already mentioned 

 as having a remarkably short canal, the three ridges are ^ in. 

 long, -A- in. high, and » broad, and terminate abruptly. In the 

 exceptional specimen referred to above the separate ridges are 

 certainly not as well marked as usual, but careful examination 

 shews that this is due to the ridges which are short, having fused 

 anteriorly and posteriorly, leaving a hollow betw^een them. The 

 remnant of a median ridge projects slightly into this anteriorly 

 and rather below its tip is the meatus urinarius. 



In some specimens the length of the median ridge is often 

 insignificant and it may gradually diminish in height, or it may 

 make a sudden drop and then continue at a lower level. On the 

 whole then the ridges in this species may be said to be on the 

 same type as, but shorter, lower, and narrower than is the case 

 in the Red and AVallaroo, and to be more like what has been 

 described in the Halmaturi. 



The vaginal cul-de-sac presents variety in details, so that it is 

 impossible to give a good description which will apply to any 

 number of specimens. In several instances the arrangement is 

 very similar ts what has been described above in the AVallaroo. 

 In one case two ridges start from the level of the lateral canals 

 und proceeding backwards along the ventral surface curve out- 

 wards and join the sides near the end of the cul-de-sac, while in 

 the median line between them there is a slight elevation which 

 extends to within i in. of the bottom of the chamber. Between 

 the median and lateral ridges on either side there are numerous 



