168 Transactions of the Royal Society of Victoria. 



muscular slip runs up each side of the sac, which opens by 

 a very short stalk with a small indication of a caecum. 

 Distally, the sac tapers considerably. 



(2) Male. — Testes, small paired bodies, very similar 

 macroscopically to the ovaries in the 10th and 11th 

 segments. A similar pair of bodies may be found often in 

 the 12th segment. The ciliated external openings of the vasa 

 deferentia are very clearly marked, but the ducts themselves 

 can only be traced backwards in sections. The ducts are 

 remarkable in that they never unite with one another, but 

 run back in the bodj^-wall parallel and close to each other 

 till they reach, and separate^ enter, the duct leading from 

 the prostate gland to the exterior. The prostate glands are 

 largely developed in the 18th segments, and from them the 

 paired ducts run down to open externally on the small 

 papillae. 



The vesiculw seoninales vary in development in different 

 specimens. They form white, solid, racemose bodies, in which 

 the spermatozoa are seen in various stages of development. 

 They may be found connected with the faces of the septa, 

 in the 11th, 12th, 13th, and 14th segments, and can always 

 be distinguished macroscopically from the testes and ovaries 

 by the definite position and size of the latter. 



Art. XVII. — Descri'ption of some Hitherto Unknown 

 Australian Plants. 



By Baron von Mueller, K.C.M.G., M.D., Ph.D., F.RS. 



[Read December 12, 1887.] 



Acacia Baileyana. 



Arborescent ; branchlets prominently angular, somewhat 

 furrowed, glabrous or beset with short spreading hairlets ; 

 leaves bi-pinnate, almost sessile or on very short stalks, 

 glabrous or the main-rhachis bearing hairlets when young, 

 as well as the branchlets and fiower-stalks somewhat 

 whitish from ceraceous bloom ; pinnules usually in three or 



