INSECUTOR INSCITI^ MENSTRUUS 167 



basal segmental white bands, widening on the sides ; venter 

 mostly whitish scaled. Legs black, the femora white at base 

 and beneath to tip; tibiae and first tarsal joint below with 

 many white scales. Wing scales black, those on subcostal, 

 second and fourth veins appearing paler. 



Type, female, No. 23833, U. S. Nat. Mus. ; Crater Lake, 

 Oregon, July 29, 1020 (PL G. Dyar). 



Variation consists in the light scales creeping forward from 

 the ante-scutellar space between the dark stripes, replacing 

 the brown ground. When the light scales surround the disk 

 of mesonotum, the marking of tahocnsis appears. It may be 

 that this is a variety of tahocnsis, but the normal small form 

 occurs with it, though sparingly. This is the commonest mos- 

 quito at Crater Lake. Occasionally the blackish mesonotal 

 stripes are weak or possibly absent. No males were obtained, 

 so the exact standing of the form must await further explora- 

 tions ; but it seems best to call attention to it by description. 



I have heretofore referred to altiiisculus Dyar from Mount 

 Rainier, Washington, as a diminutive form of tahocnsis. The 

 mesonotum of altiiisculus is dark yellow with distinct blackish 

 markings. It is difficult to see how it can be a form of 

 tahocnsis, as the evolution of the markings northward follows 

 a dif^^erent course ; but altiusciilus might be a form of masamac. 



I have a small series of females from Kaslo, British Colum- 

 bia, with almost the same markings as masantae; but these, as 

 shown by the larvae, are punctor, form centrotus, and probably 

 have nothing to do with the present form, which I take to be 

 an ally or variety of tahocnsis. 



One hundred and eighty-seven females are before me, 

 Crater Lake, Oregon, 8,000 feet, July 28-30, 1920 (H. 0. 

 Dyar). Though taken at 8,000 feet, it is evident from the con- 

 tour of the land that the breeding grounds are from 1,000 to 

 2.000 feet lower. 



Aedes (Heteronycha) cataphylla Dyar. 



This species is very close to prodotes Dyar, as previously 

 remarked by me (Ins. Ins. Mens., vii, 22, 1919 ; viii, 23, 1920). 



