384 ORDER FLAGELLATA-EUSTOMATA. 



other, recalled to mind the group of Leptomonas Biltschlii represented at PI. XIII. 

 Fig. 25. In all the examples a greater or less number of rectangular attenuate 

 amylaceous corpuscles were clearly discerned. 



Euglena rostrata, Ehr. 



Body elongate, conical, tapering posteriorly, and terminating in a short 

 tail-like process, the anterior extremity bent in a beak-like manner ; colour 

 green. Length 1-500". HAB. Pond water. 



Euglena geniculata, Duj. 



Body elongate, subcylindrical, more or less even throughout, flexible, 

 but slightly contractile, with an obliquely directed tail-like prolongation ; 

 cuticular surface smooth, colour green ; red pigment-spot conspicuous. 

 Length 1-200" to 1-170". HAB. Pond and river water. 



This species may be distinguished from E. spirogyra, which it most nearly 

 approaches, by the smooth surface of the cuticle and the obliquely directed caudal 

 ter mination. 



Euglena fusiformis, Carter. PL. XX. FIG. 58. 



Body shortly fusiform, about one and a half times as long as broad, 

 obtusely pointed at each extremity, the anterior one faintly bilabiate ; no 

 posterior tail-like prolongation ; colour rich green ; endoplast central, 

 situated between two refractive, nucleated, cell-like structures, which extend 

 round the body equatorially ; contractile vesicle and eye-like pigment- 

 spots anteriorly located ; parenchyma a rich green colour ; motion rotatory 

 and oscillating. Length 1-700". 



HAB. Fresh-water tanks, Bombay. 



This species should probably be included in the genus Amblyophis. The 

 Euglena zonalis of Carter, somewhat resembling it, is referred by Stein to the genus 

 Chloropeltis. 



Euglena agilis, Carter. PL. XX. FIG. 64. 



Body somewhat flask-shaped, inflated and widest posteriorly, attenuate 

 anteriorly ; a short, blunt, caudal prolongation sometimes present, but not 

 essential ; multiplying in its active condition by longitudinal and trans- 

 verse fission, and in its passive or encysted one by crucial or by linear 

 segmentation; colour green; movements very active. Length 1-600". 



HAB. Brackish water, Bombay. 



This species, described by Mr. H. J. Carter in his ' Notes on the Fresh-water Infu- 

 soria of the Island of Bombay,' * is remarkable for its occasional linear mode of 

 segmentation, briefly referred to in the foregoing diagnosis, the cyst-like envelope 

 that encloses the segmented fragments being so transformed, PL XX. Fig. 64, as 

 to assume an elongate subcylindrical contour. The germs, four in number, produced 

 by this fissive process are each provided with a red eye-like pigment. A somewhat 

 parallel linear mode of segmentation of the encysted animalcules has been reported 

 by Claparede and Lachmann of the Cilio- Flagellate genus Peridinium, and are 

 represented at PI. XXV. Figs. 49 and 50. 



Ann. and Mag. Nat. Hist.,' Aug. and Sept. 1856. 



