ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 257 



New Fresh-water Infusoria.* — A. C. Stokes describes some new 

 fresh-water Infusoria. 



Euglena torta n. sp. bears only the remotest resemblance to any- 

 known member of its genus. Its characteristic features are the 

 spiral grooves or keel-like ridges traversing the entire body from 

 anterior extremity to posterior acumination. 



Phacus anacoelus n. sp. resembles the foregoing in movement, but 

 in little besides. 



Vorticella smaragdina n. sp. is in colour a translucent homogeneous 

 emerald green. It has a frequently exercised tendency to a characteristic 

 change of form by retracting the borders of one side of the extended 

 body so as to produce a deep depression, and exhibits a habit of 

 sheathing the distal end of the pedicel in the posterior extremity of 

 the body. The cuticular surface is transversely striated by depres- 

 sions so fine that they are ordinarily visible only at the lateral 

 borders or after manipulation with the mirror. Minute granules 

 occasionally roughen the surface. 



V. macrocaulis n. sp. resembles V. longifilum S.K., but is distin- 

 guished by its surface striations ; whilst the pedicel is ten or twelve 

 times the length of the extended zooid. 



F. utriculus n. sp. resembles in form the marine V. striata Duj,, of 

 which it may be a fresh-water variety. In its habitat it is disposed to 

 be solitary. 



F. macrophya n. sp. bears a striking resemblance to F. cucullus 

 From., but is distinguished by the presence of cuticular striae, and 

 the absence of the cushion-like ciliary disk. 



All the above forms occur in shallow ponds in Western New 

 York. 



ZootJiamnium adamsi n. sp. was found attached to Cladophora 

 glomerata on the shore of Luna Island in the rapid water of the 

 Niagara river. In external form it resembles Kent's Z. simplex ; but 

 the cuticular surface, instead of being smooth, is finely and delicately 

 striated transversely. After the colony has been under observation for 

 a prolonged period an action takes place, unrecorded with any member 

 of the genus. " Two neighbouring zooids fold together their ciliary 

 apparatus, and their own private footstalks retract into coils without 

 disturbing the general equanimity of the community. This has been 

 observed repeatedly, the retracted muscular thread being in every 

 instance in apparent connection with that of the remainder of the 

 pedicel. This thread, however, seems to be delicate. For no visible 

 reason it soon separates into scattered fragments within the sheath. 

 In those instances just referred to an inappreciable separation had 

 probably taken place." 



A. C. Stokes also describes f the following : — 



Opercularia plicatilis n. sp. occurs in colonies of comparatively 

 such immense size that they are visible to the naked eye. In the 

 contracted phase the posterior transverse annulations closely resemble 

 those characteristic of Epistylis plicatilis Ehr. 



* Amer. Natural., xix. (1885) pp. 18-27 (8 figs.). 

 t Amer. Mon. Micr. Journ., v. (1884) pp. 226-30 (10 figs.). 

 Ser. 2.— Vol. V. S 



