800 
Transactions of the Society. 
brane apparently not present ; contractile vesicle single, spherical, 
anteriorly located ; nucleus not observed. Length of lorica, 1/450 in. 
Hah. — Brackish water about Coney Island, N.Y. 
Tintinnus tubus sp. n. PI. Y. tig. 5. 
Lorica subcvlindrical, chitinous, colourless and hyaline, less than 
five times as long as broad, tapering posteriorly, both extremities 
truncate and both open ; enclosed animalcule ovate, the temporarily 
developed posterior pedicle often exceeding the body in length, and 
adherent to one lateral border of the lorica ; frontal cilia large, and 
apparently finely fimbriated ; cuticular cilia fine and short ; peristome 
excavate, bearing at its central and deepest region an elevated, tongue- 
like projection, usually in continuous motion when the body is ex- 
panded. Length of lorica from 1/2 )0 to 1 /300 in. Hab. — Brackish 
water from a salt marsh on Coney Island, N.Y. 
That the lorica is open at both extremities has not been previously 
recorded for any other of the numerous species of the genus, but here 
the openings are conspicuously demonstrated by the continuous trem- 
bling and by the to-and-fro movements of the expanded animalcule ; 
the currents thus produced in the water carry with them bacteria 
and other minute particles into and out of the posterior aperture of 
the lorica. 
Metacystis striata sp. n. Pl. V. fig. 6. 
Body subcylindrical, often somewhat curved laterally, the anterior 
extremity slightly narrowed, but abruptly truncate ; posterior vesicle- 
like region hyaline, colourless, and often rather more than a hemisphere 
in form; oral aperture apparently followed by a short membranous 
pharyngeal passage ; cuticular surface finely striate longitudinally, and 
ornamented by transversely encircling parallel series of minute bead- 
like projections; cilia fine and numerous, apparently arising from 
the cuticular surface in close proximity to the bead-like elevations; 
nucleus subspherical, located near the centre of the body and near the 
single contractile vesicle. Length from 1/240 to 1/230 in. Hab. 
— Brackish water among decaying algae. 
Movements exceedingly rapid, and rotary on the longitudinal axis, 
with long intervals of rest in one locality, when the infusorian, almost 
periodically, suddenly retreats backward for a distance about equal to 
its length, and at once returns to its former position with one or more 
revolutions on the longitudinal axis. When the animalcule is in 
a quiescent condition the oral cilia are unfolded across the anterior 
truncated region. 
From Metacystis truncata Cohn it differs widely in size and in 
the absence of the transverse annul ations. Collected by Mr. R. O. 
Bogert, at Northport, Long Island, N.Y. 
Layynus ornatus sp. n. PI. V. fig. 7. 
Body elongate, flask-shaped, somewhat depressed, elastic, about 
five times as long as broad when extended ; anterior margin truncate, 
