where they are inclosed in minute papilla-like swellings.
Cilia-distribution controverted. Maupas and Buetschli hold that
ventral surface alone is ciliated; others (Kent and Dujardin) 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 swelling. In the
fresh-water form _L. meleagris_, it is connected with a long canal
whose swellings are frequently taken for additional contractile
vesicles (Buetschli); 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 setae on the posterior half. Contractile vacuoles are numerous,
dorsal in position and on the right side. The macronueleus 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 setae, 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 _L.
setigerum_. The flat margins are distinctly striated longitudinally,
and faintly marked radially, on the dorsal surface. Longitudinal
elevated striae 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, b). The entire body is plastic and contractile, turning
it