THE EOTIFER FAUNA OF WISCONSIN.—II. 
A Revision of the Notommatid Rotifers, Exclusive 
OF THE DiCRANOPHORINAE 
H. K. Harring and F. J. Myers 
Notes from the Biological Laboratory of the Wiscoiisiij Geological and Nat¬ 
ural History Survey. XXIII. 
INTEODUCTION. 
At the beginning of the survey of the Wisconsin rotifer fauna a 
promise v^as made to publish descriptions and figures of all the 
species found. We soon realized that this 'was likely to prove quite 
an ambitious program, and especially so in the case of the Notom¬ 
matid rotifers, the largest and also the most chaotic group of all. 
Ever since this family was first proposed, there has been a steady 
accretion of new species and a periodic shifting of the old ones, 
until it has become a veritable Serbonian bog, carefully avoided by 
everybody or, at least, trespassed upon only under compulsion. 
We do not make any pretense to superior virtue or to being con¬ 
sidered exceptions to the rule; the compulsion was, however, 
greater and became, under the circumstances, a seemingly un¬ 
avoidable necessity. A beginning was made with the review of 
the central group of the Notommatids appended to the preliminary 
list of the rotifers of Wisconsin published in volume twenty of the 
Transactions. In the present paper the remaining species are de¬ 
scribed, as far as material has been obtainable. 
No definition was given in part one of what was meant to be in¬ 
cluded among the Notommatids, and it becomes necessary to ex¬ 
plain our conception of the family. No usable diagnosis has ever 
been given and none was possible until a more detailed study of 
the group became available. The tendency in the past has been 
to include in the family Notommatidae nearly all the slow-moving, 
plant-feeding, illoricate Ploima, without any serious attempt to 
define it more precisely. We have endeavored to maintain this 
