ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 901 



ment of the cells into meshes formed by decussating spiral or oblique 

 rows, in which they are connected by stout refringent protoplasmic 

 trabeculae. The mesoderm is colourless but granular, and contains 

 small oblong connective-tissue nuclei, and refractive balls of reserve 

 nutritive material. Between the meshes of the ciliated chambers were 

 found sperm-masses about ^ mm. in diameter, the heads of the sper- 

 matozoa being distinctly visible. 



Of interest is also the discovery within the inhalent passages of a 

 new and remarkable commensal Hydroid, which Professor Schulze 

 names AmpMhracMum euplectellce ; it is a gymnoblastic form, and 

 consists of branching colonies, enclosed in perisarcal tubes ; its 

 tentacles are knobbed, and only two in number. 



Spongiophaga in Fresh-water Sponges.* — Mr. H. J. Carter has 

 established the existence of SpongiopTiaga in the fresh- as well as in 

 the salt-water sponges, having identified a new species (5. Pottsi) on 

 specimens of Spongilla. It is distinguished from the marine species 

 in that the filament does not end in a bulb at each end, though it 

 is in other respects identical. 



New Genera of Fresh-water Sponges.t — Mr. E. Potts proposes 

 to group under the genus Heteromeyenia two species which diifer from 

 the rest of those in Mr, Garter's genus of Meyenia,'^ in which he 

 grouped those species in which the statoblast is surrounded by bi- 

 rotulate spicula, the shafts of which are of a nearly uniform length. 

 In the two species above referred to, however, the uniform series is 

 broken by another of about double their length, much fewer in 

 number, somewhat regularly arranged, interspersed among them. 



A second new genus is named Carterella, in which is placed 

 Spongilla tenosperma § and C. tuhisperma in which the tube is much 

 longer than in any sponge heretofore described. Also the more 

 recent discovery C. latitenta.\\ 



Protozoa. 



Biology of the Inferior Organisms.^ — Dr. K. Eoser has under- 

 taken a series of experiments on the habituation of marine Infusoria 

 to an existence in liquids containing salts, such as urine, milk, and 

 blood ; his conclusions relating to the adaptation of the patho- 

 genous forms are worthy of notice. He makes use chiefly of 

 Polytonia uvella, and finds that if a drop of urine is brought into 

 contact with the living animal while under the Microscope, the ciHa 

 may be observed to suspend their movements, the cell-contents shrink 

 up and away from the cell-wall, and the action is the same as that of 

 drying, owing to removal of the water. Death does not, however, 

 take place, for the addition of pure water revives the Flagellate, 



* Ann. and Mag. Nat. Hist., viii. (1881) p. 222 and p. 354 (1 pi.). 



t Proc. Acad. Nat. Sci. Phila., 1881, pp. 149-50. 



X See this Journal, ante, p. 614. 



§ Ibid., p. 613. 



II Proc. Acad. Nat. Sci. Phila., 1881, p. 176. 



•II Marburg, 1881, 30 pp. (1 pi.). Kosmos, ix. (1881) pp. 475-6. 



