Harring & Myers—Botifer Fauna of Wisconsin — II. 425 
decurved at the anterior end. The rami are broad and triangular 
with a large basal apophysis; on the right ramus there is imme¬ 
diately behind the basal apophysis a broad, shear-like, striated and 
denticulate blade projecting towards the left and opposing the first 
tooth of the left uncus; it has no counterpart on the left side. The 
inner edges of the rami are not denticulate. The right uncus has 
six long teeth, gradually decreasing in size from the ventral mar¬ 
gin; to the first tooth is joined an additional rudimentary tooth, 
which is only half the length of the main tooth; the two dorsal 
teeth are very slender and joined for their entire length. The left 
uncus has five principal teeth, one very slender supplementary, 
full length tooth and the tip of a second both joined to the first 
ventral tooth; to the last, or dorsal, tooth is joined the tip of an¬ 
other imperfectly developed tooth. The middle cell of the manu¬ 
brium is long and very broad and has the usual sigmoid curvature; 
the ventral and dorsal cells are broad and plate-like. The epi- 
pharynx consists of two irregular, conchoidal structures, imbedded 
in the walls of the mastax at the sides of the mouth. The piston 
is rudimentary and attached to the ventral wall of the mastax. 
The oesophagus is fairly long and quite slender. The gastric 
glands are small and nearer the ventral side than is usually the 
case. There is no constriction between the stomach and intestine. 
The ovary is very large and in the mature animal contains usually 
from one to three developing eggs at the same time. The bladder is 
very small. The foot glands are huge and completely fill the foot; 
the;y discharge into large mucus reservoirs, contained in the hemi¬ 
spherical bulb on which the toes are seated. 
The ganglion is rather small and saccate; the minute eyespot is 
at the posterior end. A large retrocerebral sac is present, but no 
subcerebral glands. 
Total length of the free-swimming animal 200/jt; toes Sju. 
Proales gig ant ea is parasitic in the eggs of the pond snail, 
Lymnaea, possibly in several species. Stevens has given an account 
of its development in the eggs of Lymnaea auricularia and it is 
possible that the notes in the following articles may be based on 
either the eggs or the fully developed animals: 
BOMME, L., 1773. Bericht aangaande verscheiden zonderlinge zee-insecten, 
gevonden aan de zeewieren, op het strand van 't eiland Walcheren.—Verb. 
Zeeuwsch Genootsch. Wetensch. te Vlissingen. Middelburg, vol. 3, pp. 283- 
318, 1 pi. (‘^Eaderdiertje’^ in snails’ eggs pp. 302-305) 
