92 THE UNIVERSITY SCIENCE BULLETIN. 
Hydrometra martini Kirk. 1900. 
Kirkaldy, Ento., XXVIII, p. 175, 1900. (New name for lineata Say.) 
“Fuscous, hemelytra dull whitish with black nervures. Inhabits 
U. S. Body fuscous or brown, more or less deep; hemelytra dull 
whitish or dusky, with black nervures; tergum pale, quadrilineate with 
black; two of the lines on the edge and interval between the two inner 
lines, dull whitish or bright yellow; the incisures of the segments more 
or less black; beneath and feet obscure yellowish; thorax with a more 
or less obvious pale line; length seven-twentieths of an inch. This is 
very much like the stagnorum F., but the hemelytra are not testaceous 
and there is no thoracic impressed line (male). Body blue-black; thorax 
with a pale line; antenne and feet dark honey yellow; tergum and venter 
without lines.’ Say. 
Distribution: Ontario, Maine,;New York, New Jersey, Pennsylvania, 
Maryland, District of Columbia, North Carolina, Florida, Indiana, Illi- 
nois, Louisiana, Texas, Arizona, and Kansas. 
Martin, 1900, pointed out genital differences between H. inéete (A. 
martini Kirk), which he reared, and the European H. stagnorum. The 
terminal segment of the male of H. martini as seen from above is 
abruptly swollen toward the tip, which is truncate. It bears a prominent 
spiniferous tubercle which arises shortly before the tip. The lateral 
caudal margin of this segment is sinuate. 
Hydrometra australis Say. 1832. 
Say, Heter. N. Harm, p. 35, 1832. 
“Head beyond the eyes, a little longer and a little more dilated at 
tip than H. martini Kirk. Second joint of the antenne a little more 
‘dilated at tip. Abdomen with five lateral whitish points. Inhabits 
New Orleans;” after Say. Bueno, 1905, points out that the genital 
characters raise Say’s variety to a species rank, the male terminal 
segment as seen from above being swollen, but not abruptly so and 
bearing a small tubercle if any, while the lateral margin is straight, 
not sinuate as in H. martini Kirk. On plate XIII are figures of the male 
genitalia of both species, taken from Bueno. 
Found in Georgia, Florida, and Louisiana. 
B. BioLoGy OF HYDROMETRA. 
General notes. A few early notes on the behavior of this bug have 
been mentioned. These dealt with their habitat and feeding habits. 
In 1895 Arrows, in Science Gossip, gave an account of the habits of 
Hydrometra stagnorum. This was followed in 1899 by two. papers, one 
on the mating, by Palumba, and the other by Kirkaldy in his “Guide to 
the Study of British Water Bugs.” As for our own American species 
we have Martini’s interesting paper, which appeared in Canadian Ento- 
mologist for March, 1900, and Bueno’s notes in 1905 (Can. Ent.). O. 
Heidemann, in the Journal N. Y. Ent. Soc. for the same year, mentions 
the number of generations and developmental period. 
Biology of H. martini Kirk. 
Habitat. Uhler said that “it sometimes lives in the dirty holes, 
among the duckweeds, Lemna, where it wanders about over the green 
