566 Wisconsin Academy of Sciences, Arts, and Letters. 
are long and conical; there is a slight constriction near the middle 
and the proximal portion seems to be soft, while the distal por¬ 
tion has the appearance of a normal, slightly decurved toe. The 
entire length is about one twelfth of the total length of the body. 
The dorsal antenna is a small, setigerous papilla in the normal 
position; the lateral antennae are small tubules with a tuft of 
minute setae. 
The corona extends down on the ventral side of the body about 
one fourth of the total length; the post-oral portion projects from 
the surface of the body as a prominent chin. The auricles are 
very large and stout; when extended they nearly double the width 
of the head. The ciliation is continuous with the corona. 
The mastax is of the virgate type, with strongly asymmetric 
trophi, much more robust on the left side than on the right. The 
fulcrum is very long, stout, and slightly curved throughout its 
length; the anterior half is nearly parallel-sided, while the 
posterior tapers gradually to the somewhat abruptly incurved 
point. Beginning near mid-length there is on the ventral edge a 
Y-shaped groove of gradually increasing width; its sides are 
formed by two thin, corrugated lamellae, which provide increased 
surface for the attachment of the muscles of the piston; the cross 
section of the posterior portion of the fulcrum thus becomes 
Y-shaped. The anterior end of the fulcrum has a blunt, angular 
projection at the base of the rami; immediately behind this the 
right ramus has a broad, lamellar tooth with coarsely denticulate 
margin curving diagonally towards the left. Opposite this tooth 
the left ramus is deeply excavate. The alulae are very large, but 
also very unequally developed, the left being much the larger, 
very broad and strongly curved, so that it continues backwards 
beyond the base of the rami for a distance almost equal to one 
third the length of the fulcrum. The left uncus has a huge, 
blunt, club-shaped ventral tooth; closely appressed to this is a 
somewhat shorter, very slender second tooth; the third and fourth 
teeth are rudimentary and do not project beyond the crenulate 
margin of the basal plate uniting all the teeth of the uncus, which 
converge somewhat towards the inner ends; the fifth tooth is on 
the dorsal margin and projects beyond the inner edge as a spear- 
shaped point; the crenulate margin extends slightly beyond it 
dorsally. The ventral tooth of the right uncus is as broad as the 
mating tooth, but somewhat blunter and only half the thickness; 
it is followed by three straight, slender, slightly convergent teeth, 
