440 Wisconsin Academy of Sciences, Arts, and Letters. 
The mastax is of a type intermediate between the malleate and 
virgate; the primary function of the unci is evidently to crush 
the food, but there is also a piston, in this instance attached to 
the ventral floor of the mastax and perhaps incidentally to the ful¬ 
crum. The rami are triangular and apparently without teeth on 
the inner edges; the basal apophysis is large and immediately be¬ 
hind it there is a shallow groove across the rami. The fulcrum is 
short and tapers to the posterior end, which is slightly expanded. 
The unci have eight or nine long, slender teeth, clubbed at the 
tips and decreasing in size towards the posterior margin. The 
manubrium is very long and well developed; the dorsal cell con¬ 
tinues almost to the posterior end as a thin lamella. 
The oesophagus is short and slender. There is no distinct con¬ 
striction between the stomach and intestine. The ovary is of nor¬ 
mal form; the nuclei are large and as hyaline as the plasma, but 
of higher refractive index. The posterior portion of the cloaca 
appears to function as a bladder. The gastric glands are small and 
nearly spherical. The foot glands are large and pyriform. 
The ganglion is large and saccate. There is no trace of a retro- 
cerebral organ or eyespot. 
Total length lOO^i ; toes 18ju,; fepine 22/x; trophi 15[x. 
Proalinopsis staurus is not rare among floating and submerged 
sphagnum in soft water lakes and ponds. We have collected it at 
Mamie Lake, Eagle River and Lac Vieux Desert, Vilas County, 
Wisconsin, in lakes and ponds near Atlantic City, New Jersey, and 
in sphagnum ditches in Polk County, Florida. While closely re¬ 
lated to P. caudatus, it is readily distinguished by the long, slender 
toes, lack of an eyespot and the conspicuous posterior spine. It is 
difficult to narcotize and usually rolls itself up into a ball, 
armadillo-fashion. 
SubfamUy NOTOMMATINAE. 
Genus NOTOMMATA Ehrenberg. 
Notommatid rotifers with spindle-shaped, illoricate body, having 
a distin<jt constriction or neck behind the mastax, separating the 
head and the abdomen; posteriorly the body is abruptly reduced 
to a very short, usually two-jointed foot with two short, pointed 
toes; the cloaca opens dorsally at the base of the foot, under a 
projecting fold of the integument, or ^^tail.^^ 
