150 Miscellaneous. 



it the amoeboid body of the Rhizopods moves slowly. There are 

 sometimes more than twenty of these Rhizopods upon the same 

 Cancerilla. 



In its general character Oancerilla iitftitZaia approaches Ascomyzon 

 echinicola, Norm., a parasite of Echinus esculentus, and Asterocheres 

 Lilljehorgii, Boeck, a parasite of Echinaster sanguinolentus. The 

 structure of its buccal armature is intermediate between that of the 

 Poecilostoma and Siphonostoma, and seems to show the artificiality 

 of those two groups. The families Lichomolgidae, Kossm. (Sapphi- 

 rinidae, Btrtdi/), Ascomyzontidae, Boecl~ (Artotrogidae, Brady), Bomo- 

 lochidae, Glaus, and Ergasilidee, Clans, should be united into a single 

 group, for which the name Corycseidse may be retained, as already 

 proposed by Delia Valle for the Lichomolgidte. That author, how- 

 ever, goes too far when he unites under the genus Licliomolgus forms 

 of Copepoda parasitic upon Coelenterata, Gymnotoca, and Tunicata, 

 for which, as for the types parasitic upon Echinodermata, distinct 

 genera should be retained. — Comptes Rendus, April 25, 1877. 



On some Points in (lie Anatomy of tlie BJiynchobdellean Hirudinea. 

 By M. Georges Duiilleul. 



1. Dorsal organ of tlie Glossiphonise. — In a recent memoir M. 

 Nusbaum, of Warsaw, indicates the presence, in the embryo of 

 Glossiphonia complanata, Linn. {O. sexocidata, Bergmann), of a 

 provisional dorsal organ which had escaped the notice of his prede- 

 cessors. This is a pyriform cavity, limited externally by the raised 

 ectodermic lamina and internally by the somatic mesoderm. The 

 ectodermic cells bear long appendages which serve for the reciprocal 

 attachment of the young animals. This organ soon disappears, ac- 

 cording to the author, without leaving any traces. M. Nusbaum 

 adds no comment to his description. 



Having, in the course of my investigations, had the opportunity 

 of checking the author's description and ascertaining its perfect 

 correctness, the question arose, whether nothing of the same kind 

 exists in the embryos of other species of the genus GlosHphonia, 

 and particularly in that of G. bioculaia, Bergm., which, in the adult 

 state, bears a characteristic dorsal organ. My investigations of this 

 species enabled me to ascertain that its embryo presents, in the 

 very place of the dorsal organ of the adult, a formation analogous to 

 that described by M. Nusbaum in the embryo of G. sexocidata. The 

 embryos of G. marginata, Miill., are also provided with this organ, 

 which, in them as in G. sexoculata, is provisional. From these 

 observations we may conclude that the provisional dorsal organ of 

 Nusbaum in the species sexocidata and marginata represents the 

 permanent dorsal organ of the species bioculata. 



As regards the ultimate fate of this provisional organ I have 

 several times been able to find traces of it in the adult animals. 



