1887.1 ^45 [Stokes. 



Petalomonas sulcata, ?p, nov. 



Body ovate, colorless, transparent, depressed, less than twice as long as 

 broad, the surface traversed longitudinally, sometimes in a slightly ob- 

 lique direction, by from eight to ten keel-like ridges, the intervening 

 spaces being concave ; anterior extremity narrowly rounded ; the poste- 

 rior truncate, with one, sometimes two, subcentral acuminations appa- 

 rently formed by the terminal union of the longitudinal carinations ; 

 flagellum subequal to the body in length ; nucleus and single contractile 

 vesicle on opposite sides of the anterior body-half; endoplasm granular 

 posteriorly. Length of body, yi^ inch. Hab. — Pond water. Movements 

 not rapid, the oral aperture usually in contact with the submerged object, 

 the flagellum directed in advance, the anterior extremity alone vibrating. 



Urceolopsis (Urceolus ; o(/n^), gen. nov. 



Animalcules free-swimming, flask-shaped, soft, flexible and elastic, the 

 entire cuticular surface more or less covered by adherent, irregular and 

 angular sand grains ; otherwise essentially as in Urceolus. 



Urceolopsis sabulosa, sp. nov. Fig. 3. 

 Urceolus sabulosus, Stokes ; Am. Monthly Micr. Journ., vii, May, 1886. 



Body flask-shaped, soft, flexible, elastic, normally compressed and some- 

 what gibbous, about twice as long as broad, widest centrally, obtusely 

 pointed posteriorly, the entire surface more or less covered, often almost 

 concealed, by adherent, irregular and angular sand grains ; anterior ex- 

 tremity constricted to form a short neck-like prolongation, the circular 

 border thickened, expanded, and obliquely truncate ; flagellum large, 

 equaling or exceeding the body in length ; nucleus not observed ; con- 

 tractile vesicle (?) single, laterally placed near the anterior extremity ; 

 pharynx apparently extending to near the body-centre. Length of body, 

 •jj^ inch. Hab. — Fresh water with Algie. 



Traclielomonas urceolata, sp. nov. Fig. 4. 



Lorica vasiform, about twice as long as broad, the lateral margins 

 slightly flattened, anteriorly produced in a short, subcylindrical neck, the 

 aperture slightly everted, truncate, not oblique ; posterior extremity not 

 inflated, produced in an acuminate, tail-like prolongation ; endoplasm en- 

 closing numerous, probably amylaceous, corpuscles. Length of lorica, 

 -Ij inch. JIab. — Pond water. 



Trachelomonas verrucosa, sp. nov. 



Lorica subspherical, colorless, the entire surface covered with minute, 

 hemispherical elevations ; anterior extremity slightly emarginate. Length 

 and breadth, jJjy inch. Ilab. — Pond water, with Algte. 



