Harring <& Myers—Rotifer Fauna of Wisconsin — II. 417 
The subfamily Tetrasiphoninae includes only a single species; 
the mastax is notable for the unusual development of the epi- 
pharynx; a weak piston is present, but it is not attached to the 
fulcrum. The retrocerebral organ consists of a large sac and two 
long subcerebral glands. 
The subfamily Lindiinae has a highly specialized type of mastax, 
for which we propose the name ‘ ‘ cardate ’ ’; like the virgate it func¬ 
tions by suction, but the structure is very different; the mastax 
oscillates as a unit on a transverse axis, while a complicated epi- 
pharynx supports the mouth. The retrocerebral organ is limited 
to a ductless sac surrounding the eyespot. 
The subfamily Birgeinae with a single genus and species has a 
remarkable type of mastax, characterized by the virtual atrophy 
of the normal elements and their replacement by a pair of “pseud- 
unci”, hook-shaped organs of epipharyngeal origin, which may 
be protruded from the mouth to seize the prey. No retrocerebral 
organ is present. 
The subfamily Dicranophorinae includes Notommatid rotifers 
having a forcipate mastax; the entire organ is strongly compressed 
dorso-ventrally and adapted to the capture and tearing apart of 
prey by protrusion through the mouth. The retrocerebral organ 
is usually present, either as sac or glands. This subfamily includes 
a very large number of species, the great majority still undeseribed, 
and we have not been able to include them in this paper. 
The distribution of the various genera among the proposed sub¬ 
families is indicated in the list below, as well as the species in¬ 
cluded in each and a reference to the description. This arrange¬ 
ment will no doubt need modification as more detailed information 
becomes available, but if it be permitted to serve as a foundation 
upon which to erect a more permanent structure, it will have 
answered its purpose and accomplished all that was expected of it. 
Family NOTOMMATIDAE. 
Subfamily Proalinae. 
Genus Proales. 
decipiens (Ehrenberg).Vol. XX, p. 603 
sordida Gosse.XX, p. 605 
parasita (Ehrenberg). XX, p. 607 
gigantea (Glasscott) . XXI, p. 424 
wernecMi (Ehrenberg) .XXI, p. 426 
brevipes Harring and Myers.XXI, p. 428 
daphnicola Thompson . XXI, p. 430 
