428 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Double Forms of Fresh-water Turbellarians.* — E. Sekera describes 

 double forms of Macrostoma hystrix and Prorhynchus balUcus. They 

 are not artificially double, but double ah ovo. The author agrees with 

 Vejdovsky and Korschelt that all such embryonic twins arise from the 

 twin development of one ovum. 



Teratology of Planarians.t — E. Sekera describes some interesting 

 forms of Planaria albissima, showing lateral budding, a terminal bud at 

 right angles to the parent, and so on. There seems to be great plasticity 

 in the asexual multiplication and in the regenerative processes. 



Polypharyngeal Planarian.| — Al. IVIrazek describes from Mon- 

 tenegro a second poly pharyngeal species of Planaria {PL anophthalma 

 sp. n.). In addition to the main pharynx there are two accessory 

 pharynxes. In a previously described species {Ph. monteiiiyrina) there 

 were at least five, usually 9-14, pharynxes. The new species is quite 

 eyeless. 



European Temnocephalid.§— Al. Mrtizek has found in the delta of 

 the Moracii river at Scutari lake, near Plavnica, a European representa- 

 tive of the Temnocephaloidea. It was living on the small fresh- water 

 Decapod Atyaepliyra desmarestii Joly. It is smaller than any form pre- 

 viously described (from Central and South America, Madagascar, Indo- 

 Malayan, and Australian regions), and has many peculiarities. As the 

 first European representative of an important class it is of great interest. 

 The name proposed is Scniariella didactyla g. et sp. n. 



Classification of Rhabdocoela.H — A. Luther proposes some changes 

 in the systematic arrangement of the Hysterophora. He defines the 

 differences between the Catenulidte (= Stenostomidte, Vejd.) and the 

 Microstomidae. The former family appears to be a provisional group ; 

 the only character common to all its genera is the absence of a pre- 

 pharyngeal gut division. The Microstomidae include the family 

 Microstomidse, Vejd. and Macrostomidte E. Bened., which are reduced 

 to sub-families. 



Genito-intestinal Canal in Polyclads.lF^ — W. A. Haswell concludes 

 from a consideration of the structure of the female ducts in several 

 Polyclads, that the genito-intestinal passage of the Heterocotylea is the 

 homologue of a passage or receptacle which, though usually ending 

 blindly, opens in certain cases on the ventral or the dorsal surface. 

 This appears to strengthen the contention of Goto that the genito- 

 intestinal canal, and not the vagina of the Heterocotylea, is the equiva- 

 lent of the " Laurer's canal " of the Malacocotylea. 



Green Cells of Convoluta roscofiFensis.** — F. Keeble and F. W. 

 Gamble continue their work on this problem, with highly interesting 



* SB. k. Bohm. Ges., xiii. (1906) pp. 1-15 (8 figs.), 

 t Op. cit., xxxiv. (1906) pp. 1-14 (10 figs.), 

 j Op. cit., xxxii. (1906) pp. 1-18 (1 pi. and 3 figs.). 

 § Op. cit., xxxvi. (1906) pp. 1-7 (1 pi.). 



11 Zool. Anzeig., xxxi. (1907) pp. 718-23. ^ Tom. cit., pp. 643-4. 



** Quart. Journ. Micr. Sci. No. 202 (1907) pp. 167-220 (2 pis.). 



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