428 SUMMARY OF CURRENT RESEARCHES RELATING TO 



possiblo to find an efferent duct in the mass of tlio gland ; where it 

 emerges from the gland it is simple. The uterus is a cavity of con- 

 siderable size, and, when empty, lies on the outer side of the yolk-sac ; 

 on its inner free surface there arc a large number of clear hemispherical 

 cells, which are very thick-walled ; at its upper end is the narrow but 

 extraordinarily extensile oviduct. 



From this description it will bo seen that the generative apparatus 

 of Diplozoon agrees essentially with the arrangements seen in other 

 Trematoda ; it is peculiar for the passage of the canal of Laurcr through 

 the yolk-duct, and the fact that this canal docs not open on the dorsal 

 surface of the body. In consequence of the cross-like fusion which the 

 ventral surface of one animal makes with the dorsal surface of the other, 

 the end of the seminal duct of one, and the commencement of the canal 

 of Laurcr in the other pass directly into one another. The mutual re- 

 lation which is permanent in Dijjlozoon, is probably temporarily effected 

 between other mutually impregnating Trematoda. 



Second Species of Turbellarian Living on Nebaliae.* — Mr. W. 

 Repiachoif, who some years ago f described a species of Turbellarian 

 living on Nebaliae at Trieste, has since found another species at Mar- 

 seilles. He points out the differences between the two forms ; of these, 

 the most important is the slighter development of the creeping sole. It 

 will ho remembered that a sole is found in the genus Acmostomct, from 

 which Graff is inclined to derive the Platycochlides. The new type, to 

 which no name is given, does not belong to the same family or even 

 group (Alloioccela) as that genus ; and it must therefore be conceded 

 that a creeping sole may be independently developed in quite different 

 groups of the Rhabdoccelida. 



In the possession of ventral seta), the new type calls to mind certain 

 Rotifers, Dinophilus, and some Annelids, but as it cannot be supposed 

 that it is their ancestor, we must suppose that the disappearance or 

 reduction of dorsal seta3 may also occur independently in various worms. 



These results appear to the author to justify the view that among tho 

 lower Bilateria there may appear sporadically characters which in the 

 more highly organized groups become distinctive characteristics, and 

 may there be justly regarded as proofs of community of descent. On tho 

 other hand, we know that it has not yet been possible to find complete 

 series of intermediate forms between the Turbellaria and the higher 

 Bilateria, and it is possible that they were derived from Turbellaria, 

 which were as different from the Accela, Alloioccela, Rhabdocoela, 

 Polyclades, and Triclades, as there are groups one from another. It 

 may, in fact, be some day shown that the Turbellaria form a small side 

 branch of the trunk of the Metazoa. The author thinks that in our 

 phylogenetic speculations, we must be content with the fact that the 

 Bilateria are probably derived from Ccelenterata, or Coelenterate-like 

 organisms (Gastrsed). 



New Remarkable Worms.J — M. J. Kunstler has found in the 

 intestine of Solen vagina a Cestode and a Planarian, and in the tissues of 

 the body an Echinobothrium. The first of these is microscopic in size, 

 pyriform in shape, and without any indications of segmentation. At its 

 anterior extremity there is an enormous imperforate sucker; in the 



* Zool. Anzeig., xi. (1888) pp. 141-4. f See this Journal, 1885, p. 248. 



J Comptes Rendus, cvi. (1888) pp. 553-4. 



