40 Journal New York Entomological Society. [Vol. xin. 



both male ; all the others being completely apterous. One specimen was taken by 

 Mr. Davis in a plowed field, some distance from water. This Hemipteron overwinters 

 in the adult form and begins oviposition early in May. How late it may continue, I 

 am unable to say, as I have two females in an aquarium at this writing (July 15), 

 and they are still ovipositing. The females recently arrived at the adult stage, which 

 they do some time in early July from the spring ova, also oviposit at this time of 

 year, so that it is quite possible that they are double brooded, the more so that the 

 entire period of development from the ovum to the adult appears to take but little 

 over six weeks, the moults being very rapid. I feed them flies — a staple breakfast 

 food, with insects I rear — to which they take kindly, fastening their long rostra 

 into the insect even before it ceases to struggle. It seems immaterial, however, that 

 their prey should be fresh, as they appear to feed on dead insects as much as two or 

 three days old. They run on the surface of the water with considerable swiftness, 

 exactly as if they were on a solid surface. 



Family GERRID.i:. 



In this family, nearly all of Stal's different genera become subgenera, according 

 to Kirkaldy, who writes me that they are connected by intermediate forms, and in 

 deference to his exhaustive knowledge of the subject, I so consider them in the fol- 

 lowing, regarding them as subgenera of the genus Gen-is. 



Genus GERRIS Latreille. 

 G. (Hygrotrechus Stal) remigis Say. 



Lakehurst, N. J., May 30 ; Central Park, N. Y. City, April II ; Mosholu, N. 

 Y., May 4 and ( >ctober I ; Putnam Co., N. Y., September 5 ; Staten Id., N. Y., 

 March 29 ; Van Cortlandt Pk., N. V. City, July 4; Rahway R., Cranford, N. J., 

 August 6 and 20 ; Westfield, N. J., July 4 and 16, August n. 



This is very abundant in running and sometimes on still waters, from early 

 spring, as soon as the ice melts, till late fall. Winged individuals are rather rare. 



G. (Hygrotrechus) conformis Uhler. 



Putnam Co., X. Y., September 5 ; Rahway R., Cranford, X. J., August 6. 

 I have have taken only the two specimens recorded, both winged individuals. 



G. (Limnotrechus Stal) marginatus Say. 



Bronx, X. Y. City, September 30; Central Park, X. Y. City, March 22; Ft. 

 Lee Dist., N. J., July 4 and iS, October 10; Lakehurst, N. J., May 23, 25 and 

 30 ; Staten Id., X. Y., March 29, May 7, August 16; Putnam Co., N. Y., Septem- 

 ber 5 ; Van Cortlandt Pk., N. Y. City, April 18 and 15, June 6, September 19 ; Oc- 

 tober I ; Rahway R., Cranford. X. J., August 8. 



This is very common on still waters. I have found it especially abundant at 

 Van I 'ortlandt in the early spring, on the lake, where it keeps close to the shore. It 

 occurs in three forms, but I have rarely taken the wingless, the fully winged being 

 the most common. 



G. (Limnotrechus) sulcatus Uhler. 



Van Cortlandt Pk., X. Y.. October 1. 



< >ne specimen only taken. 



