314 SUMMARY OF CURRENT RESEARCHES RELATING TO 



differs in the mode of exifc and the absence of cross anastomosis. The 

 Rhabdocceles do not show the regularity of structure present in the 

 excretory system of Triclads. The apparatus of the Polyclads is still 

 less known. The fresh- water Triclads show most agreement with the 

 marine Gunda segmentata as far as structure, course of the main stems, 

 segmental arrangement of the " Knauelbildungen " and dorsal openings. 

 The segmental structure of the excretory system of the fresh-water 

 Triclads is in favour of Lang's theory, which places Gunda-like Triclads 

 as a link connecting Ctenophora and Hirudineaj. 



Autogamy in Rhabdocoelids.* — Emil Sekera finds that self -fertilisa- 

 tion has a much greater role in these forms than is usually supposed. 

 In Stenostoinidaa {Catenula, Stenostonui) the testicular follicles burst 

 within the body and liberate the spermatozoa, which reach the ovary. In 

 Macrostoma the terminal copulatory organ can be bent round into the 

 female genital aperture. A similar occurrence is noted for representa- 

 tives of the ProrhynchidEe, e.g. Prorhynchus stagnalis, the Eurnestoniidas, 

 Vorticidas, ete. By isolating individuals and observing their reproduc- 

 tion, the author seems, in short, to have shown that autogamy is general 

 in fresh-water Shabdocoelids. 



Zoochlorellse of Convoluta roscoffensis.f — F. Keeble and F. W. 

 Gamble refer briefly to their experiments proving that the green cells of 

 this Turbellarian result from infection from without. Samples of 

 colourless Convoluta reared in sterilised surroundings were put into a 

 vessel containing flagellate green organisms suspected to be the infecting 

 organisms. In the course of two or three days the infected specimens 

 of Convoluta showed in their tissues green cells identical in character 

 with those of normal Convoluta roscoffensis. The green cells are true 

 algae, belonging to the Chlorophycese, and allied to Chlamydomonas ; the 

 presence of four equal flagella suggests that they belong to the genus 

 Carter ia. 



Antarctic Rhabdoccelid.f — A. Yayssiere reports from Charcot's 

 Antarctic collection a new Rhabdoccelid in the group Greoplanidse, and 

 with relations with Rhodope. The name Rhodoplana is, therefore, pro- 

 posed. 



Deep Sea Nemertines.§ — F. F. Laidlaw gives a brief account of 

 two Pelagonemertidae, obtained by the Indian Marine Survey, which 

 represent new genera. Dinonemertes, which is closely allied to Plankto- 

 nemertes, is a broad, flattened, hyaline worm, with mouth and proboscis 

 openings separate. Bathynemertes is a new genus whose position is 

 somewhat obscure ; it differs from all the other Pelagonemertidaa in the 

 shape of the body, and when better known may require the formation of 

 a special family for its reception. 



* Zool. Anzeig., xxx. (1906) pp. 142-53. 



t Proc. Roy. Soc, series B, lxxvii. (1906) No. B 514, pp. 66-3. 



J Comptes Rendus, cxlii. (1906) pp. 718-19. 



§ Ann. Nat. Hist., xcviii. (1906) pp. 185-8 (1 pi.). 



