1886.] 5b 4 [Stokes. 



extremity. Length of body, gfj inch. Habitat — Standing pond-water, 

 with decaying vegetation. Movements rotary on the longitudinal axis. 



Trichophrya sinuosa, sp. nov. (Fig. 16). 



Body flattened, irregular in shape, the margins undulate and lobulate ; 

 tentacles fascicled, long, distinctly capitate, protruded from the marginal 

 lobes, the clusters seldom exceeding five in number ; contractile vesicles 

 multiple, marginal ; nucleus not observed. Length %^ inch. Habitat — 

 Pond-water ; attached by the entire lower surface to Anacharis. Move- 

 ments slow. 



This differs from T. epistylidis C. and L., in its much smaller size, and 

 especially in the marginal arrangement of the tentacles. The latter are 

 long, often three times the length of the body. 



Acinelactis, gen. nov. (Acineta; aicTiq). 



Animalcules subspherical, soft and changeable in form, free-swimming 

 or temporarily adherent, emitting from all parts of the surface capitate, 

 ray-like pseudopodia ; flagella two, vibratile, one temporarily adherent by 

 its distal extremity. Inhabiting fresh water. 



The single member of this previously undescribed genus differs from the 

 Actinomonas of Saville Kent in the presence of two flagella and in the 

 distinctly capitate character of the filamentous pseudopodia, the latter 

 often being conspicuously pin-like in appearance. The existence of the 

 temporarily adherent flagellum, in addition to the habitually vibratile 

 appendage, necessitates not only the formation of a new generic title, but 

 a new family group, for the reception of this singular creature, the name 

 of the latter necessarily being Acinetaclidce. 



Acinetactis mirabilis, sp. nov. (Fig. 17). 



Body subspherical, soft and plastic, often emitting short lobate pseudo- 

 podia in addition to the fine, capitate rays projecting from all parts of the 

 periphery, the last-named appendages usually bearing one or more minute 

 supplementary protoplasmic globules in the course of the ray, in addition 

 to the globule tipping the free extremity ; rays occasionally exceeding the 

 diameter of the body in length ; flagella subequal, their length about 

 twice the diameter of the zooid, originating from the anterior border, but 

 at some distance from each other ; contractile vesicle double, situated on 

 opposite sides of the anterior body-half; nucleus apparently subcentrally 

 located and subspherical ; endoplasm granular, especially posteriorly. 

 Diameter of the body ^jo inch. Habitat — Stagnant pond-water, among 

 decaying vegetation. Movements rapid. 



When in the free-swimming phase, the ray-like pseudopodia are usually 

 confined to the posterior region of the body, or they may be entirely with- 

 drawn, thus leaving the animalcule almost entirely smooth. 



