a2 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
Iowa: Ames, June 27, 1906 (H. J. Quayle). 
WISCONSIN: Saxeville, July 2, 1909 (B. K. Miller). 
OHI0: Toledo, July 6, 1915 (C. Fox). 
INDIANA: Lake Maxinkuckee (W. B. Evermann). 
Montana: Big Fork, July 25, 1903 (H. Ricker). 
Subgenus MANSONIA Blanchard. 
MANSONIA (MANSONIA) TITILLANS Walker. 
Culex titillans WALKER, Cat. Brit. Mus., Dipt., vol. 7, p. 5, 1848. 
A medium-sized dark-brown mosquito. Mesonotum with sparse 
golden scales, the integument showing, giving a frosty appearance. 
Abdomen black above, with scattered white scales, the basal segment 
yellowish; venter yellowish gray. Wing scales broad and dense, 
black and yellowish, peppered. Legs blackish brown, with scattered 
light scales on femora and tibiae, the tarsi with white rings at the 
bases of the joints, moderately broad on the hind legs. The pro- 
boscis has a small while ring beyond the middle. The palpi in the 
female are nearly half as long as the proboscis. In the male they 
exceed it by about the length of the last joint. 
The larvae are attached to the roots of a floating water plant known 
as “water hyacinth” or Pistia. These plants occur in great profu- 
sion in lakes or still rivers, and the mosquitoes may become very 
abundant in such places. They are said to be fierce in attack, and the 
bites painful. 
Distribution.—Tropical America from Brazil to Mexico, the An- 
tilles, the Everglades of Florida. 
United States Records. 
Froripa: Lake Okeechobee, March, 1906 (J. H. Egbert). 
Genus PSOROPHORA Robineau-Desvoidy. 
Psorophora RoBINEAU-DEsyoIpy, Mem. Soc. Hist. Nat. Paris, vol. 3, p. 412, 
1827. 
Janthinosoma LyNcH ARRIBALZAGA, Rev. Mus. de La Plata, vol. 1, p. 374, 
1891. 
Grabhamia THEOBALD, Mon. Culic., vol. 3, p. 243, 1903. 
Conchyliastes Howarp, Mosq., p. 155, 1901. 
Feltidia Dyan, Proc. Ent. Soc. Wash., vol. 7, p. 45, 1905. 
Ceratocystia DyaRr and KNAgs, Journ. N. Y. Ent. Soc., vol. 14, p. 178, 1906. 
Lepidosia CoQuittet, Science, n. s., vol. 23, p. 314, 1906. 
A ‘genus of tropical American origin, developed as an extreme 
specialization of the Aédes type. The species are large and showy. 
The larvae develop in transient rain pools with great rapidity, from 
egg to adult in four or five days under favorable conditions. The 
eggs are spinose to withstand desiccation, and remain on the dry 
ground for long periods awaiting rain. How long the eggs may lie 
