Sept.-Dec, I9i8.] DaVIS : MISSISSIPPI CiCADAS. 145 



faintly or not at all clouded and the abdominal seg- 

 ments margined posteriorly with brown. In fresh 

 specimens there is usually a median row of white spots 

 on the dorsum of the abdomen, .marginalis (Walker). 

 AA. Small species ; uncus wish-bone shaped, and first cross vein in the fore 

 wings starting from about the middle of the first marginal cell. 

 G. First and second cross veins of fore wings clouded. 



Expanse of wings about 90 mm biconica (Walker). 



Expanse of wings about 60 mm olympusa (Walker). 



GG. First and second cross veins of fore wings not clouded, wings clear 

 throughout and expanding about 70 mm. 

 Head rather large, front rounded, collar greenish or yellowish and 

 contrasted in color rather sharply with the brown and black of 



pronotum and mesonotum viridifascia (Walker). 



Head proportionately smaller than in the last ; front more pro- 

 truding ; collar not so contrastingly colored and fore wings 

 narrower vitripennis (Say). 



Tibicen pruinosa (Say). 



Figured in Journal N. Y. Ento. Soc, March, 1915, PL 2, fig. 2. 

 This is one of the most common species in Mississippi, and forty-two 

 specimens have been examined, twenty-two of them from Agricul- 

 tural College, Oktibbeha County. The other localities are luka, Cold- 

 water, Okolona, Rosebloom, Strongs, Greenville, Starkville, Jackson, 

 Forkville and Norris. The dates of capture range from June to 

 October. So far none have been received from the southern part 

 of the state. 



The known distribution of this species is the general region of the 

 valley of the Mississippi as far north as eastern Nebraska, and as 

 far east as Indiana. In the more elevated regions of Virginia, North 

 Carolina and southwestward, the variety winnemanna Davis, with 

 the posterior margins of the segments generally brownish, is to be 

 found, while the variety latifasciata Davis, with a broad white, prui- 

 nose mark on the third abdominal segment, occurs along the Atlantic 

 coast, close to the ocean. These two varieties may possibly be found 

 in Mississippi, the first in the higher parts of the state, and the second 

 along the coast. 



The song of pruinosa is quite unlike that of any of the other large 

 native cicadas, and may be rendered as s-zape, z-zape, s-zape. The 

 insect often remains quiet all day, singing from about 3 or 4 P. M. 

 until dark. 



