GENUS EPIPYXISDINOBRYON. 409 



GENUS XL EPIPYXIS, Ehrenberg. 



Animalcules contractile, ovate or pyriform, inhabiting solitary, sessilely 

 attached, erect, transparent loricae, to the bottom or sides of which they are 

 affixed by a contractile thread-like prolongation of the posterior extremity ; 

 flagella two in number, one short and the other long ; endoplasm enclosing 

 two longitudinal colour-bands and an anterior eye-like pigment-spot. 

 Inhabiting fresh water. 



The animalcules of this genus correspond essentially in general form and 

 structure with those of Dinobryon, and are distinguished from them only by their 

 secretion of solitary attached loricae in place of a compound branching polythecium. 



Epipyxis utriculus, Ehr. PL. XXII. FIGS. 30-33. 



Lorica elongate-conical or subcylindrical, abruptly truncate or slightly 

 everted anteriorly, widest centrally, tapering and attenuately pointed pos- 

 teriorly, about four times as long as broad ; enclosed animalcule elongate- 

 ovate or pyriform, occupying about one-half of the cavity of the lorica, 

 tapering, and continued as a thread-like pedicle posteriorly, the anterior 

 border developed on one side as a small, conical, projecting lip ; eye-like 

 pigment-spot minute ; contractile vesicle anteriorly situated, endoplast 

 subcentral. Length of lorica 1-640". HAB. Fresh water on Conferva. 



The loricae of this species, with their enclosed inhabitants, so closely resemble the 

 separate thecae and animalcules of Dinobryon sertularia that Stein originally held 

 them to be early growths only of that form. In the third volume of his ' Infusions- 

 thiere ' he, however, recognizes their independent status and fully illustrates their 

 varied aspects and habits. In some of the empty loricae figured by this authority, 

 a delicate reticulate pattern is spread over the entire surface, and apparently in- 

 dicates the presence of contained sporular bodies, or the traces of their previous 

 existence ; multiplication by fission is effected in a somewhat oblique direction. 

 Though usually found attached in some numbers to the filaments of CEdogonium and 

 other water-plants, the loricae are in most instances conspicuously isolated from one 

 another, but sometimes occur, as shown at PI. XXI. Fig. 31, in small closely set 

 fasciculi. The species has been recently obtained by the author in the neighbour- 

 hood of Ashby-de-la-Zouch. 



GENUS XII. DINOBRYON, Ehrenberg. 



Animalcules bi-flagellate, having one long and one short flagellum, 

 attached by a posterior contractile ligament within the individual cells or 

 loricse of a compound branching polythecium ; the polythecium constructed 

 through the successive terminal gemmation of the primary zooids; endoplasm 

 containing two lateral colour-bands and usually an anteriorly situated eye- 

 like pigment-spot. Inhabiting fresh water. 



Dinobryon sertularia, Ehr. PL. XXII. FIGS. 34-40. 



Constituent cells or loricae of polythecium obconical, narrowest and 

 tapering posteriorly, evertile at the mouth, slightly constricted a little 

 beneath the anterior border, joined to each other without intermediary 



