576 Wisconsin Academy of Sciences, Arts, and Letters. 
posterior ends. The eye-spot is a relatively large lenticular body 
at the posterior end of the ganglion. 
Total length 250-300//,; toes 16-20//,; trophi 40//,. 
As far as our observations go, this species is more widely and 
abundantly distributed in the United States than any other Notom- 
matid. 
The nearest known relative of this species is N. cerberus , from 
which it differs in being considerably smaller, about two thirds the 
size, and not quite so slender. The trophi are nearly identical 
with the exception of the pre-uncial teeth, which N. cerberus does 
not have. In N. galena the tail is rounded and entire posteriorly, 
while in N. cerberus it has a small median notch, not found in any 
other known Notommatid. 
Notommata Peridia Harring and Myers, new species 
Plate XLYIII, figures 1-5 
The body is elongate, fusiform, and very slender; its greatest 
width is one fifth of the total length. The integument is very 
flexible, but the outline is fairly constant. It is a very trans¬ 
parent species. 
The head segment is short and narrow, its width being about 
one half the greatest width of the body. The neck segment is 
very little wider, but nearly twice as long. The anterior trans¬ 
verse folds are well marked. The abdomen increases very slightly 
in width for two thirds of its length and then tapers gradually to 
a slight constriction at the base of the tail, which forms a blunt, 
rounded projection; on the dorsal side there are two wart-like, 
fairly prominent papillae. The foot has two small joints. The 
toes are long, about one twelfth of the length of the body, taper¬ 
ing and very slender. 
The dorsal antenna is a small setigerous papilla in the normal 
position; the lateral antennae are very long, tubular, slightly 
swollen at the base and knobbed at the ends; they are provided 
with a few very long setae. 
The corona extends down on the ventral surface for about one 
fourth of the total length. The post-oral portion projects as a 
fairly prominent chin. No auricles are present; at the anterior 
lateral angles are two V-shaped, grooved, ciliated appendages, 
which may be rudimentary auricles. 
The mastax is virgate with strongly asymmetric trophi; the 
