Clark.] 16 [June 20, 



of its members by death, Prof. Henry D, Rogers of Glasgow, 

 Scotland, and Mr. William Glen of Cambridge, and made 

 some brief remarks on their scientific services. 



Prof H. James-Clark stated that he had lately been en- 

 gaged upon an investigation of the nature of Sponger, and 

 that he had not only fully confirmed the behef of some pre- 

 vious observers that they were truly animals, but that he was 

 now able also to say that their exact classificatory relation- 

 ship was with Infusoria Flagellata^ and not with Rhizo- 

 pocla^ as Carter and others have claimed. 



He showed by a series of diagrams that they are intimately and 

 inseparably linked with the Infusoria Flagellata, such as Monas, An- 

 thopfiysa, Astasia and Anisonema, and more particularly allied to 

 certain new genera which he characterised and named, as he pro- 

 ceeded to intercalate them in their proper positions among the genera 

 just mentioned. The genus Monas he restricted to such forms as 

 have a normally pedicellated, contractile body, furnished with a more 

 or less elongate or conical, prehensile lip, and a closel}' juxtaposed, 

 arcuate flagellum, with a highly distensible mouth Ijing between 

 them. The contractile vesicle Is a globular organ which pulsates with 

 varying rapidity according to the species to which it belongs, but 

 always with a very abrupt systole. 



Bicosceca, nov. gen., might be designated, in general terms, as a 

 Monas attached to the bottom of a usually pedicellated calyx by a 

 highly muscular, spasmodically retractile cord. Its lip and arcuate 

 flagellum are attached to opposite edges of the front, and the mouth 

 lies intermediate. The contractile vesicle is single or double, and 

 situated at various parts of the body, according to the species. One 

 marine and one fresh-water species. 



Codonceca, nov. gen., unlike Dinohryon, has no lip, nor eye-spot, but 

 possesses a strictly terminal flagellum like Peranema Duj., and a flex- 

 ible contractile body, which is seated loosely in a calyx. The con- 

 tractile vesicles are two in number, and lie — at least in the only 

 species observed — on opposite sides of the middle of the body. 



Codosiga, nov. gen., has a contractile, pedicellated body; a centrally 

 terminal, arcuate flagellum ; a highly flexible and contractile, hollow, 

 membranous cylinder, or collar, which projects from the front, and en- 

 compasses the area about the mouth and base of the flagellum ; two, 

 or perhaps three, slowly pulsating, contractile vesicles, usually lying 

 on opposite sides of the body, and not far from the posterior end. 



