4o8 ORDER FLAGELLATA-EUSTOMATA. 



The possession of a flexible investing sheath or lorica and two flagellate 

 appendages chiefly distinguishes this generic group from Chrysomonas. 



Hymenomonas roseola, Stein. Pl. XXIL Figs. 14 and 15. 



Lorica ovate or ellipsoidal, soft and flexible, crenulate throughout its 

 periphery, and assuming diverse contours in accordance with the change of 

 form of the enclosed animalcule. Body of animalcule entirely filling the 

 lorica, two yellow-brown pigment-bands extending evenly throughout the 

 lateral margins. A large spheroidal fat-like or amylaceous body usually 

 present in the posterior region ; two contractile vesicles and a large vacuolar 

 non-contractile space, possibly a pharyngeal sac, situated at the anterior 

 extremity; no eye-like pigment-speck. Length of lorica 1-850". 



Hab. — Fresh water. 



Genus X. CHRYSOPYXIS, Stein. 



Animalcules solitary, ovate or spheroidal, non-contractile, inhabiting a 

 sessilely attached lorica, but not united to the same by a thread-like pedicle ; 

 flagella two in number, of equal length, produced from the centre of the 

 frontal margin, this last-named region rounded and without any projecting 

 lip -like prominence ; endoplasm enclosing two lateral colour-bands, but no 

 eye-like pigment-spot. Lihabiting fresh water. 



The animalcules of this genus are distinguished from those of Epipyxis by their 

 two equal-sized flagella, persistent form, and the absence of the connecting pedicle 

 between the body and the lorica. The single species referred to it is further 

 remarkable for the peculiar spur-shaped prolongations of the posterior border of the 

 lorica, and which penetrating in a root-like manner into the cell-wall of the ConfcrvcB. 

 to which they are usually attached, retain a close hold upon the same. 



Chrysopyxis bipes, Stein. Pl. XXII. Figs. 28 and 29. 



Lorica ovate or shortly flask-shaped, rounded and widest posteriorly, 

 with a narrow circular anterior orifice, the length but slightly exceeding the 

 greatest breadth, two diverging and acuminate spur-like prolongations 

 developed from the posterior border, these penetrating and hidden within 

 the cellular substance of the plant to which it is attached ; animalcules 

 subspheroidal, occupying the posterior half of the cavity of the lorica, the 

 two flagella projecting to a considerable distance beyond its orifice, di- 

 verging widely from one another ; colour-bands brownish, produced 

 throughout the two lateral borders ; contractile vesicles one or two in 

 number, posteriorly situated ; dividing by longitudinal fission. Length of 

 lorica 1-1600". 



Hab. — Fresh water, attached gregariously to confervoid algae. 



In his illustration of this species, Stein* indicates the presence of a presumed 

 oral aperture at the anterior extremity, close to the insertion of the two flagella. 

 Like Epipyxis ntriaihis the species is eminently social in its habits, a number of 

 individuals usually occurring crowded together upon a single cell of a Mougcotia or 

 other confervoid algal. 



* 'Infusionsthiere,' Abth. iii., 1878. 



