30 BULLETIN 1218, U. S. DEPARTMENT OF AGRICULTURE. 



tile and gradually narrowed at each end outwardly. The specimen of this 

 sex is deformed and there is some question about the permanence of the 

 characters presented. 



Holotype female, No. 24950 U. S. National Museum. Reared at Topaz, Mono 

 County, Calif., by Webb and Waite, and bearing the labels " Bishopp #7652, Br. 

 2," and " Bred July 10, 18." 



Allotype (a deformed specimen) bearing the labels, "Bishopp #7652, Br. 

 la " and " Topaz, Cal. 6-31-18." Also in U. S. National Museum. 



Nine female paratypes collected and sent in by C. F. Baker and bearing the 

 label " Mts. near Claremont, Cal. Baker," but without date of capture. 



The paratypes show some variation from the holotype in having some red 

 under the lateral spots of the abdomen and in the redder antennae. On ac- 

 count of specimens being rubbed, the body is shinier and the subcallus in 

 some specimens is more or less denuded. The venter of the abdomen is quite 

 broadly red in some of the Claremont specimens. 



The combination of characters in the diagnosis above will serve to 

 locate this species easily. It suggests most perhaps some specimens 

 of T. nivosus Osten Sacken, but the latter lacks the spot at the vertex, 

 and the wing veins are not so plainly margined. 



Description of Full-Grown Larva. 7 



Full-grown larva of Tabanus monoensis about 25.5 millimeters long. Color 

 (fig. 16, C; PI. IV, C) white with brown markings. Seen with the naked eye, 

 the larva is white with three brown spots on the anterior margin of each 

 abdominal segment except the anal, which has only two. The spots upon 

 each segment are situated in a transverse row, one in center of margin of 

 dorsum and one at each side on dorso-antero-lateral aspect. Under the binoc- 

 ular microscope these brown spots are seen to be merely accentuated parts of 

 brown bands encircling the segments as in T. punctifer. 



Prothorax with the five principal longitudinal grooves present as in other 

 species, but faint and not extending to posterior margin. Sides opaque on 

 anterior three-fourths. Back of opaque area finely striate to posterior margin. 

 Pronotum smooth and shiny. Venter with a narrow median strip of opaque ; 

 smooth and shiny on each side of this strip. Mesothorax and metathorax 

 smooth and shiny on notum and venter. Anterior margins banded all around 

 with brown opaque which on each side slightly extends posteriorly in four 

 longitudinal stripes. 



Abdomen with prologs about the same as those of T. punctifer. Sides of 

 segments finely striate. Dorsum' of sixth and seventh segments striate ; on pre- 

 ceding segments striation on dorsum is faint. Striation faint on venter of all 

 segments except anal, which back of anus is striated all around. Anus sur- 

 rounded by fine, pale yellowish pile, bordering which is a narrow circle of 

 brown opaque, without pile. From each side of anus a rather broad band 

 of brown opaque extends dorsad to margin of dorsum, where it spreads post- 

 eriorly and anteriorly. Posteriorly it continues at about the same width to 

 siphon and passes entirely around this organ. Anteriorly it goes nearly to 

 anterior margin of segment, then broadens out on dorsum into an irregular 

 splotch of brown color. Siphon very finely striate and bearing at tip a few 

 seta?. 



Described from specimens collected by J. L. Webb under Bishopp 

 No. 7652, near Topaz, Calif. 



Description op Female Pupa. 



Length of pupa (fig. 14. F; PI. IV, B) about 16 millimeters. Width of thorax 

 3 millimeters. Color yellowish brown. Tubercles on head and thorax as in 

 Tabanus punctifer, though less prominent. In the one (reared) specimen 

 available, which was prohablv nearly ready to transform when killed, the eyes 

 show almost black through the skin and there are brown spots on the thorax. 



Rima of thoracic spiracle curved into a small hook at anterior end. 



Double circlet of bristles beginning on second abdominal segment and be- 

 coming progressively longer on succeeding segments up to the seventh. Dorso- 



7 Description of larva and pupa by J. L. Webb. 



