GENUS DIPLOMASTIX. 43 [ 



vibratile flagellum, or tractellum, about twice the length of the body in full 

 extension, the trailing one, or gubernaculum, shorter and more slender ; oral 

 aperture distinct, continued as a long, tubular pharynx ; endoplasm trans- 

 parent, granular ; cuticular surface sometimes faintly striate obliquely ; 

 contractile vesicle situated close to the termination of the pharyngeal tube ; 

 endoplast oval, subcentral. Length 1-650". HAB. Fresh water. 



The species associated by Stein with the above title is identified by that 

 authority with the Trachelius globulifer of Ehrenberg and the Peranema globulosa of 

 Dujardin. A form, however, more precisely according with the last-named type 

 as examined by the author has been demonstrated, as recorded at page 225, to be a 

 developmental phase only of the Heliozoon, Actinophrys sol. 



Heteronema marina, Duj. 



Body oblong, irregularly inflated posteriorly, narrower at the anterior 

 extremity, about twice as long as broad ; cuticular surface obliquely striate ; 

 vibratile flagellum slender, equalling the body in length, trailing one much 

 thicker and longer. Length 1-420". HAB. Salt water. 



This species was obtained by Dujardin from sea-water at Cette that had been 

 kept standing for a fortnight. 



Heteronema pusillum, Perty sp. 



Body transparent, very elastic and changeable in shape, subglobose, ovate, 

 or elongate-pyriform at will, mostly the latter ; the two flagella developed 

 froni the apex of the more usually pointed anterior extremity, very long 

 and slender, the anterior one two or three times the length of the body, the 

 trailing one rather shorter. Length 1-840" to 1-768". Movements straight 

 forward, oscillating. HAB. Fresh water. 



This species, described by Perty under the title of Dinema pusillum, is referred 

 with some doubt to the present genus, being not improbably a Heteromita. 



GENUS II. DIPLOMASTIX, S.K. 



Animalcules ovate or elongate, free-swimming or temporarily adherent, 

 plastic and variable in form, but not metabolic ; flagella two in number, 

 one vibratile, the other trailing and adherent ; oral aperture well defined, 

 situated at the base of the flagella ; endoplasm colourless. Inhabiting 

 salt and fresh water. 



This new generic title is necessarily instituted for the distinction of those 

 Anisonematous forms holding an intermediate position between- A nisonema and 

 Heteronema. This is manifested by their possession of an ectoplasmic layer, which 

 while sufficiently soft and plastic as to permit the animalcules to assume slowly 

 and under special conditions diverse individual contours, never exhibits that high 

 degree of elasticity and contractility productive of rapid and protean changes of 

 contour as met with in the last-named generic type. On the other hand, it 

 is never so firm and indurated as obtains in Anisonema. Two of the species here 

 described have been recently referred by Stein to the genus Bodo of Ehrenberg, 

 but evidently possess nothing in common with the representatives of that generic 

 group as recognized in this volume or associated with that title by most recent 

 authorities. 



