1906.] TURBELLARIA OF THE CAPE VERDE ISLANDS. 717 



the Avails. Consequently each chamber-cavity is in section rather 

 crescentic, with the horns of the crescent directed upwards. Each 

 is connected with the terminal duct by a well-defined stalk or 

 ' neck.' On either side there are some fifteen or so of these 

 chambers. 



Lying over every one of these is a deeply-staining giomerulus- 

 like mass of cells, each glomerulus having an oval or nearly 

 circular outline in section and consisting of a central mass of 

 cells forming a core, and lying round these an irregular scanty 

 layer serving as a capsule. The cells of the central core-mass in 

 one or two cases are wedged at its lower end in amongst the cells 

 of the roof of the small chamber lying immediatel}^ below them ; 

 in other cases there seems to be a very minute channel leading 

 from the centre of the core into the chamber, but this if it exists 

 is so small that I cannot consider it satisfactorily demonstrated. 

 The cells which make up the core have abundant protoplasm, which 

 stains rather deeply and is very finely granular. Some few of 

 these cells are larger than the others, more deeply stained, and 

 pyriform. 



Lastly, in the saine transverse plane as the two ducts described 

 above, but in the middle line, the lumen of another conical or 

 pyriform organ opens into the ventral depression, behind the 

 penis, directed forwaixls in this case and armed with a short 

 cylindrical stylet. At the hinder end of this organ, v/hieh must 

 be regarded as an intromittent prostate, its lumen ends blindly. 

 The outer wall is muscular, the fibre being almost entirely 

 circular ; and between the muscular wall and the lumen lies 

 prostatic tissue crowded with rather large feebly staining granules. 

 So that the complicated male terminal apparatus consists of 

 (1) a penis into whose lumen the vasa deferentia open ; (2) a pair 

 of pi-oblematic compound ducts lying on either side of the penis ; 

 (.3) an inti-omittent prostate lying behind the penis. 



Scarcely less elaborate are the terminal parts of the female 

 organs. The vagina opening in the middle line, close behind the 

 depression in which the outlet of male organs lies, runs at first 

 upwards and forwards surrounded by numerous shell-glands. In 

 this part of its course it is widened transversely and has a muscu- 

 lature but feebly developed. Soon the vagina turns backwards, at 

 the same time becoming narrow and cylindrical, so that the 

 circular muscle coat is relatively, if not actually, thicker. At a 

 level behind its opening to the exterior this part of the vagina 

 receives the terminations of the two uteri, which run nearly 

 transversely from without inwards to join it. Behind this it 

 widens again immediately to form a spherical accessory vesicle 

 whose non-muscular walls consist of a single layer of cubical non- 

 ciliated epithelium. This vesicle contains spermatozoa. 



The uteri pass outwards and a little forwards from the vaoina, 

 until they reach a point on either side well to the outside of the 

 .main-gut and at a lower level, where each turns backwards and 

 runs longitudinally. In this longitudinal part of their course 



