ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 975 



guished from all known forms by the combination of rounded prominences 

 and transverse striations. (10) V. parasita was found attached to the body 

 of an aquatic worm. (11) V. conica has a much elongated body, and when 

 contracted exhibits posterior aunulations. It appears to be much less timid 

 than most Vorticellse, for the cover-glass may be repeatedly and somewhat 

 violently disturbed without in any way altering the expanded animal ; this 

 may be explained as due to the activity of the supporting host, for the 

 Cyclops leaps through the water with rapid and often long-continued move- 

 ments, (12) Epistylis tincta resembles E.flavicans somewhat closely in some 

 of its characters, but differs in having the contracted zooids pyriform and 

 not subspherical in shape, and the ultimate divisions of the pedicle more than 

 twice as long as the expanded bodies. In the hinder part of the bodies of 

 most representatives of this new species there was a cluster of refractive and 

 apparently crystalline bodies, the nature of which is quite problematical ; 

 they often occur in young colonies composed of only two zooids, and are 

 absent from older zoodendria formed of many. (13) The last new form is 

 LagenopJirys obovata, which in form and size most nearly resembles L. vagi- 

 nicola, but differs from it in the less cordate aspect of the lorica, and the 

 narrower anterior region. A woodcut is given illustrating these forms. 



New Hypotriclious Infusoria from American Fresh Waters.* — Dr. 

 A. C. Stokes describes as a new genus Onychodro^nopsis, which differs from 

 Onychodromus chiefly on account of the soft, flexible, and uncuirassed 

 condition of the body. On the dorsal surface there are numerous short, 

 hispid set^e ; 0. fiexilis is the new species, Tachysoma agile is the type of a 

 new genus which is distinguished from Pleurofricha by the absence of the 

 supplementary ventral series of styles, and the softness and flexibility of 

 the body; these latter characters, with the absence of caudal setae, 

 distinguish it from Stylonychia, which it otherwise somewhat closely 

 resembles ; as it has the marginal setas of the posterior border interrupted 

 it cannot be placed with Oxytricha ; its systematic position is probably 

 between the last-named genus and Histrio ; T. mirabile, and T.parvistylum, are 

 the other new species of the genus. The other new species described in the 

 paper are Litonotus vermicularis, which may be 1/60 to 1/30 in. long, and 

 the largest and mature forms are visible to the naked eye as fine white 

 threads gliding through the water ; Loxodes magnus, which is 1/40 in. 

 long ; Oxytricha hifaria, 0. hymenostoma, 0. acuminata, and 0. caudata ; 

 Histrio inquietus and complanatus ; Euplotes variabilis ; and Ghilodon vorax, 

 as to which we have the following very interesting account : — 



" The infusorians under observation fed voraciously on certain linear 

 diatoms (probably a species of NitzscMa), with which the water teemed, 

 the frustules often being considerably longer than the body of the animal- 

 cule in its normal condition, and after being engulfed, consequently, 

 extending through the entire length of the infusorian, and stretching the 

 cuticular surface at both extremities until at these points the limiting 

 membrane became the merest film. Before the process of engulfing was 

 actually witnessed, it was an interesting problem as to how the diatom 

 became freed from the posterior region of the pharyngeal passage which 

 extends almost to the centre of the body. . . . During the passage of the 

 frustule, when the cuticular surface of the rear margin of the body has 

 reached its limit of extension, the pharyngeal tube, containing one end of 

 the long diatom, suddenly and violently rotates forward until its normal 

 position is completely reversed, and the diatom consequently slips out. 

 The act is probably only to a certain extent voluntary, being effectually 



* Ann. and Mag. Nat. Hist., xx. (1887) pp. 104-14 (1 p].). 



3 s 2 



