236 ENTOMOLOGICAL SOCIETY 



discoidal part of subcosta, radial part of subcosta very fine and often obso 

 lete at terminus ; no distinct plerostigma ; radius straight and only curved 

 at tip, running into the anterior costa; stem of first fork as long as cubi- 

 tus. stem of second fork twice longer than that of the first, straight and 

 parallel with radius; first furcal twice shorter than the stem, terminating 

 rectangularly on the costa, second furcal very long, three times longer 

 thtin the first, forming a right angle therewith, gentlj' curved at outer half 

 and ending very obliquely on the costa, third furcal a little shorter than 

 the second, slightly undulated ; fourth furcal longer than the second or 

 third, nearly straight and as long as the stem of second fork; tip of wing 

 halfway between radius and fourth furcal; radial cell very high; margi 

 nal cells large and of nearly equal size, though quite different in shape. 



$. Genital plate very tall, much longer than the genital segment, 

 without lateral appendages, front edge slightly convex, hind edge slightly 

 sinuate near tip which is subtruncate, with the posterior angle acute and 

 projecting posteriorly; forceps a little lower than the plate, simple, 

 slightly widening from base to near the tip which is rounded, front and 

 hind margins straight. 



9- Genital segment as long as the three preceding ventral segments 

 together, upper plate gently narrowed posteriorly into a moderately long 

 acute, straight point; lower plate a little wider and shorter than the upper 

 one, lower edge ascending, tip short acute. 



Described from numerous specimens collected by Mr. A. 

 Koebele in Placer county, Cal., on Arctostaphylos pungcns, dur 

 ing the months of September and October, and at Marble Val 

 ley, Cal., in the middle of July. The specimens from the latter 

 locality are a little darker than those from Placer county. It 

 occurs also in the mountains of southern Arizona (Hubbard and 

 Schwarz). 



Type. No. 8143, U. S. National Museum. 



Besides the variations in the color of head, thorax and wings 

 referred to above, a remarkable variety occurs in California 

 which may be readily mistaken for a different species and which, 

 for this reason, deserves especial mention and a distinct varietal 

 name. 



Var. niveipennis, n. var. 



Color of head and thorax just as variable as in the form described above, 

 usually pinkish red, or brownish yellow, or brownish red, thorax usually 

 a little darker, surface of head and thorax often a little shining, sculpture 

 usually less evident. Wings snow-white, the posterior costa sometimes 

 margined with red or tesselated with minute red spots, surface having the 

 appearance of being covered with fine white powder, which causes the 

 venation to be less distinct than in the typical form and the sculpture to 

 become obsolete. The sinuation of the costa in anterior basal cell is ab 

 sent; abdomen and legs uniformly yellow. Sexual characters as in the 

 typical form.. 



