48 
BULLETIN OF THE LABORATORIES 
is clearly seen and all the details of the water vascular system may be 
made out with ease. The lateral vessels are tortuous canals, while 
upon them are seated beaker cells, the flask-shaped base of which, con- 
nects directly, by means of a curved tube of less diameter, with the 
main canal. The mouth of the flask is directed downwards and 
has a small opening near which is the point of insertion of a long 
cilium which extends upward into the flask, where it is constantly in 
motion. There seems to be no reason to doubt that by means of 
these beaker-cells the vascular system is in communication with the 
perivisceral cavity. The foot is comparatively slender and has, aside 
from distinctly cross-striate muscles, two large foot glands which open 
in the ends of the rather long dagger-shaped claws. A pair of fine 
bristles springs from the dorsal surface of the last segment of the foot. 
The following measurements were taken ; 
I. lorica .22 
mm. 
long. 
No. 2. .22 No. 3. 
.24 
“ .14 
mm. 
wide. 
.14 
•15 
foot .06 
mm. 
long. 
.06 
claws .07 
mm. 
long. 
.07 
.072 
jaw capsule .06 
mm. 
long. 
.06 
.048 
Found in Minnesota during the whole summer among water plants. 
Euchlanis -ampuliformis, sp. n. 
[Plate 77 , Fig. 3.] 
This species, which deviates toward Salpina, is smaller than the 
above and, in outline, 'is somewhat flask-shaped. The back is cari- 
nate and the flat ventral j^late is excavated posteriorly with a cordate 
opening. The head is produced and densely hairy below. The 
maxtax is small, but the cervical eye is very large. The nuclei of the 
ovary are very conspicuous, although the egg is not as large in propor- 
tion as in the above. The foot is four-jointed and the claws are elon- 
gated and somewhat curved. The lorica is .16 mm. long, the claws 
.08 mm. Another individual measured .20 mm. and the claws were 
.12 mm. long. This species was seen but twice, June i8th, 1884, 
in Minnesota. 
POLYARTHRAEA. 
The family includes the two genera, Triarthra and Polyarthra. In both 
genera the foot is wanting and appendages of the sides of the body take its place. 
The body is not segmented except anteriorly and the form is not definite. The 
genus first mentioned has two lateral and a ventral appendage, while in Polyarthra 
the appendages are collected in groups upon the opposite sides. In both genera, 
the egg is carried about as in Amirecs^ 
