BY J. J. rLETClIEE, B.A., E.Sc. GoT 



reticulations, especially towards the posterior portion of the cul- 

 de-sac. Sometin-:es the ventral surface presents only obscure 

 longitudinal folds and radiating trabecular without any other 

 marked feature. I hare several times met with the reticulate 

 structure described by Professor Owen in his specimen. 



In two specimens the remains of a well-marked longitudinal 

 septum such as the same distinguished anatomist has described 

 in the cul-de-sac were met with. This septum which runs along 

 the dorsal wall, extended in one specimen completely across tiie 

 cavity for a distance of i in., near the bottom of the cul-de-sac^ 

 while for the rest of its course, as throughout in the other case, 

 it was only partial. To see this septum the cul-de-sac should be 

 laid open laterally or from the ventral surface but as it was more 

 suitable for my purpose, the dissections in all my other specimens 

 were made intentionally from the dorsal aspect, and accordingly 

 the septum was injured or overlooked, both in this and the other 

 species mentioned in this paper. 



On comparing the urogenital organs of J/, mcfjor with those of 

 the Eed Kangaroo and the Wallaroo, which two agree pretty 

 well as has been already pointed out, the following points of 

 difference are noteworthy. Macrojms major has (1) as a rule no 

 direct communication between the cul-de-sac and the uro2:enital 

 passage ; (2) the lateral canals considerably longer ; (3) the 

 urogenital canal shorter by about one-third of its length ; and 

 (4) ridges, in the urogenital canal as a rule on the same tvpe^ 

 but of smaller dimensions than is the case in the other two species, 

 and exceptionally the ridges may be absent altogether, whereas 

 in the Wallaroo and Eed they are always present as far as we 

 Ivuow at present, I sus])ect too that the median vagina is 

 probably relatively longest in M. major, and on this point as on 

 that of the relative lengths of the lateral canals, a series of 

 measurements would be interesting, but up to the present, want 

 of leisure and of additional specimens of 0. roJjustus and 0. rufus 

 has prevented the investigation of these details. 



