438 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
extremity to a short distance from the end, and usually approaches the left edge. An anus is present 
near the posterior end of the dorsal swelling. Trichocysts are numerous on the ventral surface, and 
often on the dorsal surface, where they are inclosed in minute papilla-like swellings. Cilia-distribution 
controverted. Maupas and Biitschli hold that ventral surface alone is ciliated; others (Kent and Dujar- 
din) that cilia are uniformly distributed. The entire body, dorsal and ventral surfaces alike, are 
uniformly striated. The contractile vacuole lies posteriorly, on the right side and in the dorsal swell- 
ing. In the fresh-water form L. mdeagris, it is connected with a long canal whose swellings are 
frequently taken for additional contractile vesicles (Biitschli); in the marine form described below 
the canal is not developed and a series of vacuoles takes its place; these are all contractile. The 
macronucleus may be single, double, quadruple, band-formed, or rosette-formed, Movement is steadily 
progressive and peculiarly gliding. Fresh and salt water. 
Loxophyllum setigerum Quenn. ’67. 
Synonyms: Litosolenus armatus Stokes ’93; Litosolenus verrucosa Stokes ’93. 
The body is flattened, irregular in outline, obtusely pointed anteriorly, the point being turned to 
the right; rounded posteriorly. The left edge is nearly straight, the right considerably arched with a 
few setas on the posterior half. Contractile vacuoles are numerous, dorsal in position and on the right 
side. The macronucleus is beaded, the several spheres connected. 
Variety armatum (Cl. & Lach.). (Fig. 32.) 
Under the name Litosolenus armatus, Stokes described a form from brackish water near New York, 
which should unquestionably be referred to the genus Loxophyllum, and I believe to Quennerstedt’s 
species setigerum. While the latter possesses only a few setse, the former has a number of them, and 
Stokes described his species as having a variable number. For this reason I include the Woods Hole 
form under the tentative name armatum, as a variety of Quennerstedt’s X. setigerum. The flat margins 
are distinctly striated longitudinally, and faintly marked radially, on the dorsal surface. Longitudinal 
elevated strire also run the length of the dorsal hump and upon the entire ventral surface. The ventral 
surface is alone ciliated. Upon the edges of the flat border are sharp-pointed, colorless, spine-like 
processes, situated at equal distances around the entire periphery except at the anterior end. Each 
spine is thick at the base and tapers to a full point which is curved upward — i. e. , dorsally ( fig. 32, 
a, h). The entire body is plastic and contractile, turning its leaf-like edge readily over objects upon 
which it creeps. The cilia are fine and uniform, with a tendency to lengthen in the oral region. 
Length 100// ; greatest width assumed on contraction 85// ; when normal about 50 p. 
Genus LIONOTUS Wrzesniowski ’70. 
(Incorrectly called Litonotus by many. Entz '84; Gruber ’84; Biitschli ’88; Kent '81; Schewiakoff ’89; Shevyakov ’96.) 
The body is elongate and somewhat lance-shaped, widest at the central part and tapering to a 
point at the anterior end. The posterior end may be similarly tapered or rounded. The anterior end 
frequently proboscis-like, flat, and flexible, while the entire body is more or less elastic and contractile. 
The right side is flattened and alone provided with cilia, while the left side of the body proper is 
arched; on the left side of the proboscis is a row of coarse cilia resembling an adoral zone, and a row 
of trichocysts. A long peristome stretches down the thin, ventral side of the proboscis, and the mouth 
proper is situated at the junction of the proboscis and body; the mouth, as a rule, is invisible. The 
ciliated right side alone is striated in the majority of species. The contractile vacuole may be single 
or multiple, usually in the posterior region of the body and dorsal in position. The macronucleus is 
usually double, rarely single or quadruple, but may occasionally break into numerous smaller pieces. 
Movement, free-swimming or gliding, with especial tendency to get under clumps of foreign matter. 
Fresh and salt water. 
Lionotus fasciola Ehr. Fig. 33. 
Synonyms. Amphileptus fasciola Ehr. ’38; Dujardin ’41; Lachmann ’56; Cohn '66, Diesing '65. 
Loxophyllum fasciola Claparede & Lachmann ’58; Balbiani 61 
Loxophyllum duplostnatum Maupas 83; Shevyakov ’96 
Body frequently brown or brilliant yellow in color, somewhat sigmoid in form with tapering 
anterior end, the extremity of which is turned dorsally. The proboscis is about half the entire length 
