500 ORDER HOLOTRICHA. 



Supplementary Species. 



The Holophrya coleps of Ehrenberg, thus characterized : — " Body oblong, cylindri- 

 cal, rounded at both extremities ; colour whitish. Length 1-430" to 1-280" " — 

 is identified by Stein with the Coleps inennis of Perty, and elevated by him to the 

 rank of a new genus, distinguished by the name of Plagiopogon. 



Holophrya lateraUs, S. K. Pl. XXVI. Fig. 46. 



Body cylindrical, evenly ovate or elliptical, a little over twice as long as 

 broad ; cuticular cilia conspicuous, arranged in numerous closely approxi- 

 mated, even, longitudinal rows ; contractile vesicle lateral, situated a little 

 in advance of the median line ; endoplast inconspicuous ; endoplasm 

 enclosing innumerable, minute, spherical corpuscles, in addition to the 

 ordinary digestive vacuoles. Length i-ioo". 



Hab. — Fresh water : Bombay (H. J. C). 



An animalcule answering to the above diagnosis, and possessing the charac- 

 teristic terminal oral and anal apertures of the genus Holophrya, is figured and 

 briefly described, without name, in the manuscript notes kindly placed at the author's 

 disposal by Mr. H. J. Carter. The species differs essentially from all previously 

 described members of the genus in the lateral instead of terminal location of the 

 contractile vesicle. The flexibihty of the integument of this type was demonstrated 

 by the flattened or contorted shapes it assumed in passing and pressing against 

 confervoid filaments or other objects in the water. 



Genus VI. OTOSTOMA, Carter. 



Animalcules free-swimming, ovate, subcylindrical, entirely ciliate ; oral 

 aperture inferior, subterminal, conducting to a short, recurved, indurated 

 pharyn.x, the contour of which, in profile; resembles that of a human ear ; 

 anal aperture, endoplast, and contractile vesicles conspicuous. 



Excepting for the peculiar conformation of the phar}Tigeal tube, the single type 

 of this genus corresponds essentially with the genus Nassula ; a still more marked 

 divergence in the same direction is noticeable in Cohn's new generic type, Helico- 

 stoma, next described. 



Otostoma Carter!, S. K. Pl. XXVI. Figs. 55-58. 



Body ovate, rounded at each extremity, not quite twice as long as 

 broad, slightly narrower anteriorly ; oral aperture situated in a depression 

 on the ventral surface, at a distance of about one-third of the length of the 

 entire body from the anterior extremity ; pharyngeal tube ear-shaped, 

 longitudinally plicate, recurved towards the posterior extremity ; anal 

 aperture postero-terminal ; cilia of cuticular surface short and even, dis- 

 posed in fine parallel longitudinal lines ; endoplast fusiform, subcentral ; 

 contractile vesicles two in number, separate from one another, often, as in 

 Paramcscium aurelia, exhibiting a stellate outline. Length i-lOo". 



Hab. — Fresh water, among Nitella : Bombay (H. J. C). 



Mr. H. J. Carter, in his brief description of this interesting form,* having omitted 

 to confer upon it any other than a generic title, the author has much pleasure in 



• Ann. Nat. Hist.,' Feb. 1S56. 



