462 
Wisconsin Academy of Sciences, Arts, and Letters. 
and a long dorsal section. The alulae are very prominent. The 
unci have only one tooth, slender and clubbed at the tip; there is 
no basal plate. The manubria are very long and their general 
direction is nearly at right angles to the fulcrum, so that they 
almost reach the dorsal side; the basal plate is small and its edges 
are parallel to the strongly curved anterior end of the principal 
rib; the posterior branch is very slender and slightly recurved. 
The piston is bulky, but not very powerful. The epipharynx con¬ 
sists of two slender, strongly curved rods, imbedded in the walls 
of the mastax at the sides of the mouth. 
The oesophagus is short and slender. There is no constriction 
between stomach and intestine. The gastric glands are small and 
nearly spherical. The ovary is irregularly elongate and reaches 
from the bladder nearly to the mastax; the nuclei are large and 
irregularly polygonal. A fairly large bladder is present. The 
two foot glands are tapering and fully as long as the foot. 
The ganglion is large and saccate. There is no trace of the 
retrocerebral organ. The eyespot is well towards the front of the 
head and seems to be seated on the mastax instead of the lower 
surface of the ganglion, as it follows the movements of the mastax. 
Total length 180-200/i; foot and toes 55-60/a; toes 16-18/*; 
trophi 22/*. 
Pleurotrocha rohusta is rather rare; we have found it in Oneida 
and Vilas Counties, Wisconsin, and in ponds and ditches around 
Atlantic City, New Jersey. As this species has nothing in common 
with Mikrocodides chlaena except the fused toes, it has been trans¬ 
ferred to Pleurotrocha, with which it seems to agree fairly well. 
No good reasons ever existed for referring it to Mikrocodides; the 
fused toes can not be considered a generic character to the exclu¬ 
sion of everything else. The supposed identity of the corona in 
the two species is an error; neither M. chlaena nor P. rohusta has 
the mouth at the center of the corona; as pointed out by De Beau¬ 
champ, M. chlaena has a corona of the type of Cyrtonia, and the 
mastax is malleate. 
Genus CEPHALODELLA Bory de St. Vincent. 
Notommatid rotifers with prismatic or spindle-shaped, illoricate 
or partly loricate body, having a slight constriction or neck sep¬ 
arating the head and abdomen and passing without definite limit to 
the rudimentary foot, which is not jointed and has two slender toes. 
