GENUS PANOPHRYS. 533 



situated a little in advance of the median line, presenting at diastole a 

 stellate outline ; the cortical layer containing abundant closely set tricho- 

 cysts. Length 1-180". HAB. Bog water. 



Ophryoglena oblonga, Stein. 



Body ovate, rounded posteriorly ; oral fossa elliptical, straight, set more 

 forwards than in Q. atra ; endoplast spheroidal, no endoplastule ; eye-like 

 pigment-spot usually present. HAB. Fresh water. 



Ophryoglena caeca, Stein. 



Form, and position of oral aperture coinciding with C. oblonga, but 

 larger and thicker ; endoplast oval, having an attached endoplastule ; no 

 eye-like pigment-spot. HAB. Fresh water. 



This and the preceding form are briefly characterized by Stein as above in 

 the ' Sitzungsberichte der konigl. Bohmischen Gesellschaft der Wissenschaften ' for 

 December 1860. 



Ophryoglena Wrzesniowskii, Mereschk. sp. 



Body scarcely twice as long as broad, transparent, somewhat variable 

 in form, more or less evenly ovate, rounded at each extiemity, the posterior 

 end usually slightly the wider; oral fossa situated a little to the right 

 of the median line at a short distance from the anterior extremity, en- 

 closing apparently two opposed membranous flaps ; cuticular surface 

 longitudinally striate, finely ciliate throughout ; the cortical layer com- 

 pletely filled with large, closely approximated, rod-like trichocysts ; con- 

 tractile vesicle single, located close behind the oral fossa; endoplast 

 spherical, subcentral. Length 1-175". 



HAB. Fresh water : river Dwina and Lake Onega (Mereschkowsky). 



This species is figured and described by Mereschkowsky, in his account of the 

 Infusoria of Northern Russia,* as a species of Glaucoma; from his figure and 

 diagnosis given, it is however evident that the animalcule is a true Ophryoglena, 

 differing but slightly from the common forms O. atra and O. acuminata. The bilabiate 

 aspect of the oral membrane, upon which alone its claim for admission to the first- 

 named genus is based, has been frequently noted by the author in connection with 

 the last-named types. 



Supplementary Species. 



The Ophryoglena flavicans of Ehrenberg, and O. citreum of Claparede and Lach- 

 mann, characterized by the presence of a fringe of larger cilia round the oral 

 aperture, are here referred to the genus Panophrys of Dujardin. The Ophryoglena 

 griseo-virens of Perty, is apparently a variety only of O. atra. 



GENUS II. PANOPHRYS, Dujardin. 



Animalcules ovoid, more or less persistent in shape; oral aperture 

 situated at the bottom of a pocket-like fossa, which originates on the 



* ' Archiv f. Mikrosopische Anatomic,' Bd. xvi., 1878. 



