November 1, 1895.] 



SCIENCE. 



569 



of Tristomum ovale by the speaker, so 

 that Tristomum ovale, Goto, is a synonj'm 

 of Trist. teve, Verrill. (2) Phylloaella 

 hippoglossi (P. J. V. Beneden). This is the 

 species called Epibdella hippoglossi by v. 

 Beneden. The distinction between the two 

 genera is that Epibdella has a pair of well- 

 developed anterior suckers, while Phyllo- 

 nella has none. The vagina is present and 

 opens into the yolk reservoir, as in other 

 species of Tristomidffi. The ' vesicules se- 

 minales ' of v. Beneden is the prostate 

 gland and the internal cavity of the penis, 

 while the vesicula seminalis of Cunningham 

 is the vagina. (3) Polystomum Hassalli, 

 n. sp. This species was found by Dr. Has- 

 sall, of Washington, in the bladder of Kino- 

 stern on pennsylvanicum. Body 1.5 mm. 

 long, egg-shaped, genital hooks 16(3) and 

 of the same size. Ovary sometimes on the 

 right, sometimes on the left side. Intestine 

 bifurcated, not branched. The Polyst. ob- 

 longum of Leidy is not Polj^st. oblongum, 

 Wright. (4) Hexacotj'le thunninse (Par. 

 et Per.). This is the Octocotyle thunninse 

 of Parona and Perugia. The form of the 

 body, the structure of the suckers as well 

 as that of the vagina, shows that the species 

 ought to be brought under the genus Hexa- 

 cotyle. 



In conclusion the speaker referred to the 

 so-called ' grosse Zellen.' Under this name 

 structures of various natures have been in- 

 cluded, viz., (1) ganglion cells, (2) con- 

 nective tissue cells, (3) gland cells. 



Prof. S. J. Hickson (Manchester) in speak- 

 ing of the classification of the Alcyonaria 

 referred to the difficulty there is in finding 

 sufficiently distinct characters to separate 

 the Alcyonaria Gorgonacea. He considers 

 that the Corrallidse and Briarcidaj should 

 be included among the Alcyonacea and not 

 among the Gorgonacea. 



The author then referred to some diffi- 

 culties in the determination of species from 

 museum specimens of Alcyonarians. 



Prof. E. Blanchard (Paris) made a 

 communication upon the leeches of the 

 Dutch East Indies and of the Indo-Malayan 

 region. 



M. Dollfus (Paris) read a paper on 

 the distribution of the isopod family, 

 Oniscidw, in Europe. This group is par- 

 ticularly favorable for such studies, for most 

 of its species exactly follow climatic zones. 

 Most of them belong to the Mediteri-anean 

 region, stricto sensu ; some present cui'ious 

 phenomena of penetration toward the north 

 or south, and a single one is ubiquitous. 

 Three species of Armadillo, one of Eluma 

 and twenty-five of Armadillidimn were con- 

 sidered. 



Baron E. de Selys de Longchamps (Liege) 

 presented a paper entitled ' Progress in 

 knowledge of the Odonata.' 



M. Piepers (the Hague) spoke of sup- 

 posed cases of mimicrj' among the insects, 

 and expressed doubts concerning several 

 so-called facts to which a place has been 

 accorded in science before thej' have been 

 sufficiently studied. 



Prof. Perrier (Paris) gave an account 

 of the marine laboratory on the island of 

 Tahiton, of which he is the founder and di- 

 rector. It supplies facilities for researches 

 in pure science, also for those bearing on 

 fisheries and pisciculture. It is furnished 

 with all necessary appliances and covers a 

 space of 4 hectares. 



M. Bolsius (Oudenbosch) read a paper 

 upon the nephridea of the leeches, which, he 

 contended, are separate from the ciliated 

 organs. Prof Kowalevsky (St. Petersburg) 

 then gave a paper on contributions to the 

 anatomy of the Clepsines. 



Prof. Julin (Liege) communicated the 

 work of his pupil, E. Legros, on the struc- 

 ture and development of the sexual or- 

 gans in Amphioxus and the Ascidians. In 

 both groups there is close homology in the 

 formation of the sexual products. The 

 cavity of the ovary and testis is homologous 



