nexo Infusoria from American Fresh Waters. Ill 



Uroleptus SpJiagni^ sp, nov. (PI. I. fig. 20.) 



Body clavate or broadly obovate, depressed, three times as 

 long as broad, extensile posteriorly ; widest and rounded ante- 

 riorly, somewhat curved towards the left-hand side, thence 

 tapering to an attenuate, usually pointed, caudal prolongation, 

 which, when extended, equals or exceeds in length the 

 greatest width of the body ; lip crescentic, prominent ; ante- 

 rior border somewhat curved towards the dorsal aspect, tlius 

 forming a conspicuous transverse groove or depression on the 

 frontal region of the dorsum ; peristomial field broad, extend- 

 ing through the anterior one third of the ventral surface, its 

 posterior termination curved toward the right-hand side, the 

 left-hand margin bearing the adoral and a series of fine par- 

 oral cilia, the right-hand border finely ciliated and supporting 

 an undulating membrane ; frontal styles four or five ; ventral 

 setai in two median lines extending into the caudal prolon- 

 gation ; marginal setaj projecting posteriorly, those on the 

 left-hand side originating at the posterior extremity of the 

 peristomial field in close proximity to the ventral set^e, and 

 extending obliquely and longitudinally towards the posterior 

 portion of the left-hand border; contractile vesicle single, sphe- 

 rical, on the left-hand side of the peristome-termination,near the 

 body-margin ; nucleus double, elongate-ovate, with a laterally- 

 attached nucleolus ; dorsal hispid seta3 numerous, fine and 

 short ; anal aperture on the left-hand border of the dorsal 

 surface near the origin of the caudal prolongation. Length 

 of body j^o inch. 



Hah. Standing water, with Sjyhagnicm. 



The caudal prolongation is very frequently extended until 

 it becomes almost filiform. It is then also oftea arcuately 

 curved. lu the numerous specimens examined I have been 

 able to determine the existence of but one nucleolus, which is 

 attached to the anterior nuclear nodule. Even the use of 

 reagents failed to disclose a second. 



EXPLANATION OF PLATE I. 



Fi(/. 1. Heteromita variabilis, X 075. 



Fi(/. 2. Paramonas alata. Diagram. 



Fig. 3. Clustenema socialis, X 1225. 



Fif/. 4. Cyclanura orhiculata, X 330. 



Fifi. 5. Chry!io}jyxisurceolafa, X 1350. 

 Figs.QSc&a. Chrysopyxis dispar, X 1350. 



Fig. 7. XJrotricha platystonia, X 330. 



Fig. 8. TiUlna campyla, X 400. 



Fig. 9. Amphileptiis mouilatus, X 100, 



Fig. 10. Loxophyllum voras, X 2(30. 



