ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 41 



gordius. With some modifications of detail, his results strongly resemble 

 those of Bergh. He finds that abnormalities at times occur in the proto- 

 nephridia of Nephelis which bring these closer to those of Polygordius 

 than Bergh thought. The protonephridia of Nephelis strongly resemble 

 these of Aulastomum, but the latter are more complex, and suggest 

 comparisons with the permanent excretory organs of the adult or of 

 related simpler forms. The author agrees with Bergh that the proto- 

 nephridia of leeches are derived from those of such a form as Poly- 

 gordius, but are phylogenetically highly specialised structures. 



Nematohelminth.es. 



Mode of Filarial Infection.* — Sigg. B. Grassi and G. Noe first of all 

 corroborate Bancroft's suggestion that the Filarite pass from mosquito to 

 man only in the act of biting. Secondly, in the case of Filaria immitis 

 in Anopheles, they show that the embryos develope in the Malpighian 

 vessels, pass into the cavity of the hotly, and reach the prolongation of 

 this in the labium. They explain in detail the very interesting way in 

 which the larva? pass from the labium in the act of biting. 



Development of Sclerostomum equinum.f — A. Conte describes the 

 ovoid eggs with their delicate shells, the formation of the blastula with 

 two large initial endoderm-cells, the embolic gastrulation, and the ap- 

 pearance of the two initial mesoderm-cells, the formation of two ventral 

 mesoderm-bands and of four longitudinal rows of endoderm-cells, the 

 beginning of the stoinodseum and the nervous system, the endodermic 

 origin of the primitive intestine, and its strange subsequent replace- 

 ment by a non-endodermic secondary intestine. The retrogression of 

 the primitive endoderm recalls what Heymons and Lecaillon have de- 

 scribed in certain insects. 



Platyhelminthes. 



Enterostoma mytili (v. Graff).* — Heir H. Sabussow describes this 

 Turbellarian from the gills of the edible mussel. One of the most 

 remarkable features is the combination of the genital aperture with the 

 mouth and the opening of the resulting porus communis at the posterior 

 end of the body. Perhaps, like a form described by Bohmig from 

 Lessina, it should be separated from the genus Enterostoma. A position 

 between Allostomina and Gylindrostomina is suggested for both. 



Two Large Species of Distomum.§ — Herr H. v. Buttel-Eeepen de- 

 scribes D. ampullaceum sp. n., 47 mm. in length by 22 mm. in breadth 

 and 16 mm. in thickness, said to have come from a cetacean in the Indian 

 Ocean, but more probably (according to the author) from a Coryphsena 

 which seafarers sometimes call a dolphin. A second large form, D. 

 siemersii sp. n., from the stomach of Sphyrsena barracuda in the Atlantic 

 Ocean, measured 31 by 12 by 10 mm. 



New Genus of Distomid8e.|| — Herr Th. Odhner finds it necessary 

 to establish a new genus — Gyrnnophallus — for Distomum deliciosum Olss., 



* Centralbl. Bakt., 1"= Abt., xxviii. (1900) pp. 652-7. 



t Comptes liendus, cxxxi. (1900) pp. 840-8. 



t Zool. Anzeig., xxiii. (1900), pp. 256-63. § Tom. cit., pp. 5S5-98 (9 figs.). 



|| Centralbl. Bakt., l t0 Abt., xxviii. (1900) pp. 12-23 (4 figs.). 



