56 MISC. PUBLICATION 336, U. S. DEPT. OF AGRICULTURE 
Southeast it has been recorded from Arkansas, Mississippi, and 
Tennessee. A reported occurrence in New Orleans, La. (146), is con- 
sidered questionable. It is one of the four species of the subgenus 
Janthinosoma occurring in the United States. Matheson (1/7) has. 
described unusual male genitalic characters for the species, and 
Rozeboom (135) has given the first description of the larva, which 
he found to have long antennae, similar to those of Psorophora ferox. 
The two species were taken together and were found only in shaded 
pools. The adults of both species have the last two segments of 
the hind tarsi white, but in fe7oa the broad whitish scales of the 
mesonotum are scattered (as in P. cyanescens) whereas in horrida 
they are segregated in patches at the sides (as in P. varipes). 
PSOROPHORA DISCOLOR (Cog.) 
Psorophora discolor occurs sparingly throughout the South. The 
larvae have unusually large, S-shaped antennae and long anal gills. 
The adults have well-defined wing spots and are distinguished from 
P. signipennis by the characteristic distribution of these spots, as 
given in the key. The writers’ specimens of this species are from 
Mound, La. (G. H. Bradley), Loyston, Tenn. (S. E. Shields), 
Paducah, Ky. (G. E. Quinby), McComb, Miss. (T. T. Bracken), 
Decatur, Ala. (W. V. King), Leon County, Fla. (B. V. Travis), and 
Monroe, La. (E. B. Johnson). Previously published records are for 
Brewton, Ala. (105), Lee County, Ga. (134), Scott, Ark. (142), 
southeastern Arkansas (79), Huntsville, Ala. (736), Charlotte, N. C., 
Clarksdale, Miss., and Baton Rouge, La. (50). 
PSOROPHORA PYGMAEA (Theob.) 
This tropical species has been recorded once from the Florida keys 
(Key West) (85). The collection was made in 1901 and the species 
has not since been reported from the United States. 
PSOROPHORA SIGNIPENNIS (Cogq.) 
Psorophora signipennis occurs in the arid western regions. It 
was reported from Arkansas by Dyar (51), and Carpenter (47) has 
since reported it from Dyess, Ark. The writers have a single larva, 
apparently of this species, from Mercedes, Tex. (sent in by P. T. 
Riherd), in which the hairs at the tip of the air tube are rather 
long, about two-thirds as long as in larvae of P. cyanescens from the 
same locality, and do not therefore agree with the characters usually 
given in keys for the separation of these species. The larva, how- 
ever, is readily distinguished on other characters, as shown in the 
present key. 
Genus MansoniA Blanchard 
(Syn., Taeniorhynchus L.-Arr., Coquillettidia Dyar) 
The mosquitoes of this genus lay their eggs in rafts on marshes 
or lakes having certain kinds of aquatic vegetation. Upon hatching, 
the young larvae descend below the surface of the water and attach 
themselves by inserting the tip of the air tube into the stems and 
roots of aquatic plants, through which they obtain air. The pupae 
