219 

 Usinger: Hemiptera 



new . Ohio .J"ur. 



Fig. 7:33. Hydrometra martini Kirkaldy, tip of abdomen. 

 o, dorsal view of male; t, side view of male; c, ventral view of 

 male; d, dorsal view of female; e, side view of female; f, ventral 

 view of female. Hydrometra lillianis Bueno. g to /, views com- 

 parable to above. 



Key to California Species of Hydrometra 



1. Numerous pits on all 3 pairs of acetabula, scarcely 

 evident on posterior pair; body surface velvety; clypeus 

 truncate anteriorly; 2nd antennal segment only about 

 1/3 longer than 1st. segment (13:10, 15:11); male 

 abdominal processes widely separated, blunt, inclined 



outward (fig. 7:3>2>g-l)\ Santa Barbara, California. 



lillianis Bueno 1926 



— Two pits only on anterior and middle acetabula, poste- 

 rior acetabula unpitted; body surface not conspicuously 

 velvety; clypeus rounded anteriorly; 2nd antennal seg- 

 ment more than twice as long as 1st segment (56:25); 

 male abdominal processes slightly arched, transverse, 

 separated by a distance equal to transverse length of 

 a process (figs. 7:32; 7:33a-/); Colorado River drainage, 

 Yuma to Needles, Death Valley. . .martini Kirkaldy 1900 



REFERENCES 



DRAKE, C. J., and H. M. HARRIS 



192§. Concerning some North American water striders 



EV \ns 



ill'- Hungarian Mai 



in the i ami Ij . Ann. \lu . 



wit h dcscripl ion. i .1 Hire- 

 Sci., 28:269-276. 

 HUNGERFORD, II. B., and N. E 

 1934. The Hydrometridae of 

 Museum and other .studi* 

 Nat. Hungarici, 28:31-112, 12 p] . 

 MARTIN, J. (). 



1900. A study of Hydrometra lineata. Oan;ul. Km., .12:70- 

 76, pi. 3, figs. 7-8. 

 TORRE-BUENO, J. R. de la 



1926. The family Hydrometridae in the Western Hem- 

 isphere. Entomologiea Americana VII (ilk.), pp. S3-128. 



Family MACROV E L IIDA E 



Macrovelia is a monotypic genus which shows certain 

 affinities to the South African Ocellovelia China and 

 Usinger (1949). Whether these two annectent types 

 belong in a single subfamily (or family) or as separate 

 groups does not concern us here. Certainly Macrovelia 

 is a unique type in the North American fauna, the 

 six-celled hemelytra being without parallel here. 

 The well-developed ocelli and apical claws and the 

 single dorsal abdominal scent gland of the nymphs 



Fig. 7:34. Macrovelia hornii Uhler, female, Mokelumne Hi 

 Calaveras Co., Calif., May 21, 1931 (R. L. Usinger). 



