SMITH : INFUSORIA OF KANSAS. 155 



This species occurs rather commonly in pond water. I have found the 

 greatest possible amount of variation among the individuals of this species. 

 In a single culture I found animals differing widely in size, in relative 

 length of proboscis, and in general shape of body. Some of the individuals 

 were three times as long as others. Some had long probosddes while those 

 of others were short and inconspicuous. In some there was a definite 

 pointed tail-like prolongation, in others the posterior end was bluntly 

 rounded. 



I also noticed a difference in the nucleus of the various individuals. 

 Most of the books on classification speak of this species as having a monil- 

 iform nucleus; but although I stained a great many of the animals with a 

 variety of stains, I was unable ever to demonstrate such a nucleus. In 

 some of the smaller individuals a band-like nucleus, like the one shown in 

 the figure, was distinctly visible. However, in the great majority of cases 

 the nucleus was plainly scattered. Calkins in his Protozoology speaks of 

 Dileptus as having a scattered nucleus, and this, I believe, is the normal 

 form in the adult animal. (Fig. 11, plate XXXV.) 



Genus Loxodes Ehr. 



Body elongated, leaf-like, flexible, but not persistent in form. Ventral 

 surface flat, longitudinally striated, and finely ciliated. Dorsal surface 

 slightly convex, smooth, and without cilia. Stronger cilia around the 

 margin of the body. Mouth preceded by a ciliated, slit-like peristome. 

 Pharynx tubular, and strengthened by an indurated membrane. Many 

 nuclei. Contractile vacuoles uncertain. 



Loxodes rostrum Ehr. 



Body flattened, highly flexible, about four times as long as broad. An- 

 terior extremity pointed and curving toward the left. Posterior extremity 

 also pointed and curving slightly toward the left. Mouth on left border of 

 ventral surface at some distance from the anterior end and preceded by a 

 slit-like peristome which runs forward to the apex of the anterior extrem- 

 ity. Walls of pharynx strengthened by a brownish induration. Short 

 marginal setae present. Nuclei small and numerous. Posterior part of 

 animal very vacuolar. Contractile vacuoles unidentified. 



Found in stagnant pond water. 



Length varies from 165 to 500 microns. Length of type specimen, 187 

 microns. (Fig. 12, plate XXXV.) 



Genius Trachelitis Ehr. 



Body oval or elliptical. Anterior end produced into a short, dorsally 

 projecting proboscis with round oral aperture at its base. Pharynx short 

 and longitudinally striated. Entire body highly vacular. Cuticular surface 

 finely and uniformly ciliated. Macronucleus central, sometimes single and 

 elongated, sometimes double. 



Trachelitis ovum Ehr. 



Body ovate or nearly spherical, prolonged anteriorly into a short, 

 flexible, snout-like projection. Mouth circular. Pharynx conical, longi- 

 tudinally striated. Cilia fine and arranged in longitudinal rows. Mac- 

 ronucleus spherical to band-like, sometimes double. Cytoplasm extremely 

 vacuolar. Contractile vacuoles small and numerous. 



3 — Univ. Scl. Bull., Vol. IX. No. 13. 



