150 Wisconsin Academy of Sciences, Arts, and Letters. 
Mirror Lake at Belton; pools near Fond dn Lae; stagnant 
waters near Lake Winnebago and other places near Appleton; 
Twin Islands and Mud Creek at Lake Spooner; and in small 
bodies of fresh water at Tarpaulin Cove and Hobska Light, 
near Wood’s Hole, Mass. 
Arrenurus megalurus, nov. var. of A. glob at or Mull. 
Fig. 2, ar-f , Pis. XIV—XV. 
In collections containing A. globator there were often found 
closely related individuals with stouter bodies and appendages. 
They also show strong resemblance to A. caudatus Be Geer and 
A. Stjordalensis Thor. 
The body is longer than wide and slightly angular, and is 
depressed between the eyes. The most characteristic feature 
is a conical projection in front, of each eye, larger than the 
same humps noted in A. globator. The dorsal shield is slightly 
eight-sided. A lateral view shows the anterior side walls 
strongly arched; in this it resembles A. globator and differs 
from A. caudatus. The appendage differs from the nearest re¬ 
lated forms in being greatly arched up in the middle 1 ; and in the 
shape of the end, the middle part of which here runs out beyond 
the side corners with a slight rounded incision. In lateral view 
the form is like that figured by Piersig and Henman for A. 
globator. In other details it closely resembles the form here 
identified as A. globator. The differences between A. megar 
lurus and A. caudatus are best seen by comparing the lateral 
views. In the latter, the region inside the dorsal line is strongly 
arched and the appendage is lower. In both dorsal and ventral 
views, the 'appendage of A. megalurus is seen to be constricted 
at the base, narrower here than at the end, the difference being 
greater than in A. globator, and forming in this respect a 
marked contrast to A. caudatus. The same thing is true of the 
genital areas which here form rolls extending beyond the body 
walls. In legs, palpi, epimera and hairs the variety closely re¬ 
sembles the species. 
The difficulty of identifying these individuals has been in¬ 
creased by finding some degree of variation among them. 
