71 259 



is forced outward, the whole hind part of the l)ody is curved and tlic urogenital 

 canal is now in two tempi, figured in figgs. 6 — 7, forced outwards and turned inside 

 out; in this case it is altered into a hyaline cup traversed by the ductus seminalis 

 and furnished at its base with a wreath of fine not vibrating cilia. In Ibis position 

 at the moment when the sperma is to be thrown over into the female, the testis 

 has altered its form, now being much more slender and more longitudinally stretched. 

 If the animal is held in this position by means of pressure, we see the bladder 

 slowly fill itself; it cannot be emptied, and as the figure shows, it has now a 

 constriction in its lower part. The short ureter and its opening in the urogenital 

 canal is now very conspicuous; the canal in its outer part is covered with short 

 cilia. Sometimes I think I have seen a series of parallel transversal stripes as indica- 

 ted in the figure in this shape of the bladder. 



I may add that the variation in form and size of A. priodonta, so characteristic 

 in the female (Langhans 1905, p. 171; 1906, p. 439; W.-L. 1908, p. 82), has not 

 been observed in the male sex. 



A. Brightwelli Gosse. 



Male: BrightweU 1848, p. 153. 

 Dalrymple 1849, p. 340. 

 Hudson-Gosse 1888, p. 122. 

 Rousselet 1901, p. 1. 

 Daday 1891, p. 84. 

 Tab. VII, fig. 2. 



Dalrymple (1849, p. 340, Tab. 34, fig. 11—14) has described the male; in the 

 following the description is given in somewhat abbreviated form. 



The male is about three-fifths the size of the female, generally resembling in shape, 

 but more flattened at the lower part or fundus, and more prolonged at the side, corresponding 

 to the vaginal opening in the female, and which in the male presents a similar valvular 

 opening though comparatively smaller in extent. Within this valve is observed a short 

 canal, leading to a large spherical bag which may be distinctly seen, filled with molecular 

 bodies in constant tremulous motion. From this body (the sperm-sack) a short but thick 

 rounded body projects into the canal, before mentioned as leading to the lateral opening; 

 around the extremity' of this projecting process, and even within it to a short distance, is a 

 visible ciliary motion, indicating a canal. The whole organ is regarded as a penis; a very 

 exhaustive description is given of the muscles which draw in and out the presumed penis. 

 Lateral canals, vibratile tags and contractile vesicle as in the female, but there are no mand- 

 ibles, pharynx, oesophagus, pancreatic glands or stomach; globular masses in the body cavity; 

 they are to be regarded as rudiments of the stomach. 



HuDSON-GossE (1889, p. 122, PI. XII, lig. 1 c) gives a figure of the male but liardly any 

 description. 



Rousselet (1901, p. 1) only remarks that the male is without a luimp. 



Daday (1891, p. 84) only says: „Körper cylindrisch, oval, hinten etwas abgestutzt, ohne 

 Fortsätze. Grösse 300— 500/^." 



Description. The male in many respects differs very conspicuously from 

 the male of A. priodonta. It is much more globular, almost isodiametric, still somewhat 



