108 Dr. A. C. Stokes on new Hypotrichous 



Holosticha vernalis, sp. nov. (PL III. fig. 5.) 



Body subelHptical, about four times as long as broad, very 

 soft and flexible ; both extremities rounded, the anterior lip 

 short, crescentic ; the peristome extending backward through 

 about one third of the ventral surface, the right-hand margin 

 ciliate, the adoral series on the posterior half of the left-hand 

 border directed across theperistome-fieldtowards the righthand, 

 the anterior half directed towards the left hand ; frontal styles 

 five or six, scattered, the three anterior largest; ventral setae 

 forming two median rows, beginning in close proximity to 

 the frontal styles ; marginal setee longest at the posterior 

 border, those on the left-hand side gradually leaving the body- 

 margin and approaching the peristome ; anal styles from five 

 to eight, usually fimbriated ; contractile vesicle spherical, near 

 the centre of the left-hand side ; nucleus not observed ; dorsal 

 hispid setje numerous. Length of body y^ inch. 



Hah. Shallow pools in early spring, with alg^. 



TachySOMA [ra'x^ixi, swift ; (Tcofia), gen. nov. 



Animalcules free-swimming, soft, and flexible; frontal 

 styles from eight to ten, the three anterior usually the largest ; 

 ventral styles five, scattered; marginal setas at some distance 

 from the lateral borders, interrupted on the posterior margin j 

 anal styles five ; caudal seta3 none ; dorsal hispid setse usually 

 numerous and conspicuous. 



Tachysoma agile, sp. nov. (PI. III. fig. 6.) 



Body elongate oval, about four times as long as broad, both 

 extremities evenly rounded ; peristome-field arcuate^ extend- 

 ing through about one fourth of the ventral surface, without 

 a right-hand or reflected inner border ; marginal setas in close 

 proximity to the five scattered ventral styles ; anal styles 

 five, large, often finely fimbriated, and with a tendency to 

 form two groups, the two elements on the right-hand side 

 usually extending obliquely towards the right ; contractile 

 vesicle near the centre of the left-hand body-margin, gib- 

 bously extending the region at complete diastole ; nucleus 

 double, each ovate nodule with an external subspherical nucleo- 

 lus ; dorsal hispid setee long, fine, clothing the dorsal surface in 

 several longitudinal rows. Length of body -^\-^ inch. 



Hah. Pond-water. 



I was at first disposed to identify this with Pleurotricha 

 ecMnata (C. & L.), S. K. ; but that form, as suggested by 

 Kent, proJDably belongs to another genus, being relegated to 

 Stein's Pleurotricha with some doubt, as the supplementary 



