150 Journal New York Entomological Society. [Vol. xiii. 



width of scutellum one and one third times its length; length of insect 

 8.2 to 10.2 mm variabilis. 



9 (S) Vertex six to eight times the synthlipsis ; width of pronotum one and four 

 fifths times its length; width of scutellum one and one sixth times its 



length ; length of insect 10.7 to 12 mm uhlerL 



IO ( I and 7) Medium-sized robust species. 



II (14 and 17) Vertex at least three times the synthlipsis. 



12 (13) Vertex three to four and one half times the synthlipsis ; width of 



pronotum two and one half times its length ; width of scutellum 

 one and one half times its length ; length of insect II to 14 mm. 



mexicana. 



13 (12) Vertex three times the synthlipsis; width of pronotum twice the 



length ; width of scutellum one end one quarter times its 



length; length of insect 12. 1 to 14. 4 mm irrorata. 



14 (if and 17) Vertex less than three times the synthlipsis. 



15 (16) Vertex two to two and one half times the synthlipsis ; width of 



pronotum twice the length ; width of scutellum one and one 

 fifth times the length ; length of insect 12.1 to 17 mm lutea. 



16 (15) Vertex two and one half times the synthlipsis; width of pronotum 



one and six sevenths times its length ; width of scutellum one 

 and one fifth times its length ; length of insect 13. 1 to 14 mm. 



montezuma. 

 17(11 and 14) Vertex not twice as wide as synthlipsis. 



18 (19) Vertex one and one third times the synthlipsis; width of pro- 



notum one and two thirds times its length ; width of scutellum one 

 and one third times its length ; length of insect 8 to 13 mm. 



shooterii. 



19 (18) Vertex but slightly wider than synthlipsis; width of pronotum 



twice the length ; width of scutellum one and one fifth times the 

 length; length of insect 12. 6 to 15. 5 mm insulata. 



1. Notonecta indica Linne. 

 Notonecta indica. 



1771. Linne, "Mantissa Plantarum," p. 534. 



1900. Kirkaldy, " Entomologist," p. 10.* 



1904. Kirkfldy, " Uber Notonectiden," Wien. Ent. Zeit., p. 94. 

 N. americana. 



1775. Fabr. , Syst. Ent., p. 690, etc.* 



181 1. 01., Erie. Meth., VIII, p. 389 * 



1886. Uhler, Ch. List, p. 28. 



1894. Uhler, P. Z. S., Lond., p. 223. 



1897. Kirk., Rev. Not., Tr. Ent. Soc. Lond., p. 408. 



1901. Champ., Biol. C.-A., Rhvnch. II, p. 370, Tab. 22, fig. II, female. 

 .V. unifasciata. 



1857. (?) Guerin, Le Moniteur, p. — .* 



1858. Guerin, Bull. Soc. Zool. Acclim., LV, p. 581. 

 1897. Kirk., Tr. Ent. Soc. Lond., p. 426. 



