28 THE GENUS TRACHELOMONAS, 



Trachklomonas veurucosa Stokes. (PL iv., f.l). 



Lorica globosa, minutis papillis achrois sparse ornata; collo 

 nullo. 



Diam. 18 /x. Lismore 225; very rare. 



Cf. Stokes, Infus. U. S., p. 88. He gives diam. 24 /x. It should, 

 perhaps, be arranged as a variation of 7'r. volvocina, but I have 

 seen only one specimen. 



Trachelomonas scabra, n.sp. (PI. iv., f.2, 3). 



Lorica ovalis pequaliter rotundata vel postice acuminata; collo 

 iato brevissimo; membrana scabra non autem ordine granulata. 



Long. 29-33, lat. 20; coll. alt. 2-4, lat. 4-5 /x. 



Lismore 238, 242. 



This species is very distinct; all its forms are easily recognised 

 by the characteristic membrane. The surface is rough all over, 

 not with granules but with minute protuberances irregularly 

 disposed. The colour is generally pale yellow. 

 Var. LONGICOLLIS, n.var. (PI. iv., f.4-6). 



Lorica et membrana ut in forma typica, collo autem longissimo, 

 recto vel obliquo vel curvato, interdum ore everso. 



Long. 29-33, lat. 19; coll. alt. 6-7, lat. 3-5, lat. oris 6 /x. 



Lismore 238. 



Var. OVATA, n.var. (PL iv., f.7, 8). 



Lorica ovata, anteriore ovalis, posteriore acuminata, extremo 

 producta conica; collo quadrato vel brevissimo. 



Long. 34-46, lat. 20-22; coll. alt. 2-6, lat. 5-6; caud. long. 4-6, 

 lat. 3-4 /x. 



Lismore 237, 238, 241. 



Var. SCROBICULATA, n.var. (PL iv., f.9). 



Lorica ut in var. ovata, glabra autem et crasse scrobiculata 

 paene reticulata; collum interdum annulo basali instructum. 



Long. 36-42, lat. 20-22; coll. alt. 3-4, lat. 4-6; caud. long. 2-5 //.. 



Lismore 236. 



The outline in this form is smooth, showing that the surface 

 is level, but the membrane itself is so perforated with wide scro- 

 biculse as to be almost reticulated. 



