GENUS MICROGLENA. 403 



spot usually developed ; flagellum single, equalling or exceeding the length 

 of the body ; contractile vesicle single, anteriorly situated. Length 1-600" 

 to 1-1200". HAB. Fresh water. 



This minute species is referred by Stein, with some doubt, to the Monas ochracea 

 of Ehrenberg. Multiple fission within a comparatively large spheroidal cyst or 

 capsule, closely corresponding with the reproductive process recorded of the type 

 last described, as figured by the same authority, is reproduced at PI. XXII. 

 Figs. 5 and 7. 



GENUS III. MICROGLENA, Ehrenberg. 



Animalcules free-swimming, illoricate, plastic and changeable in form, 

 usually more or less ovate or elongate ; oral aperture distinct, anteriorly 

 placed, communicating with a dilated pharyngeal cavity ; flagellum single, 

 terminal ; endoplasm green or yellow, enclosing two supplementary longi- 

 tudinally placed coloured bands and one or more eye-like pigment-spots ; 

 contractile vesicle and endoplast conspicuous. Inhabiting fresh water. 



Microglena punctifera, Ehr. PL. XXII. FIG. 10. 



Body somewhat variable in form, elongate-oval or obconical, widest and 

 rounded anteriorly, tapering and bluntly pointed at the posterior extremity, 

 about twice as ' long as broad ; flagellum attenuate, vibratile, issuing from 

 the oral aperture, scarcely equalling the body in length ; pharyngeal cavity 

 capacious, subspheroidal or pyriform ; endoplasm yellow, the two lateral 

 coloured bands produced through the entire length of the body ; two minute 

 red eye-like pigment-spots at the anterior extremity ; contractile vesicles 

 numerous, spheroidal, four or six in number, located around the border of 

 the pharyngeal excavation ; endoplast ovate, subcentral. Length 1-620" 

 to 1-500''. HAB. Fresh water. 



The diagnosis of this species, and also of the genus Microglena, is here amended 

 in accordance with the figures given by Stein in the recently issued volume of his 

 ' Infusionsthiere.' The following form not having apparently fallen under the notice 

 of this authority, has associated with it an imperfect description formulated only upon 

 the figures and brief description originally given by Ehrenberg. 



Microglena monadina, Ehr. 



Body shortly ovate or subspheroidal, evenly rounded at each extremity ; 

 flagellum equalling the body in length ; endoplasm brilliant green, enclosing 

 a single, anteriorly situated, scarlet, eye-like pigment-spot ; pharyngeal 

 excavation capacious ; endoplast (?) band-like, subcentral. Length 1-2400" 

 to 1-720". HAB. Pond water ; movements rotatory. 



A very distinct band-like structure, apparently corresponding with the ovate 

 endoplast of the preceding type, is indicated by Ehrenberg in the various figures 

 given of this species, as also a large anterior pharyngeal excavation. By Pritchard it 

 is recorded as occurring among slimy water plants in the neighbourhood of Hamp- 

 stead and Finchley. 



2 D 2 



