1917] Pacific Coast Species of Xylococcus 155 



transverse rows corresponding to segments; a few pores of same type 

 as in stage four (PI. XIV, fig. 13) interspersed among abdominal hairs; 

 a polygonal protuberance at end of body. 



Male, sixth stage, adult. — " Length; body 2 mm., width across thorax 

 .8 mm., wings 3 mm. long by 1 mm. broad, expanse about 7 mm.; color 

 of head and thorax dark brown, abdomen yellow, with bands of brown 

 above and below, wings cinereous; veins blackish; only one distinct 

 branch to discoidal vein." (Coleman). 



Eyes large, prominent and coarsely facetted. Antennae ten-jointed, 

 reaching middle of abdomen; joints one and two short and stout; joint 

 three longest; remaining joints diminishing in length and diameter 

 towards apex; all bearing numerous irregularly distributed fine hairs. 

 Two pairs of wings; front pair cinereous with irregularly reticulate 

 surface; discoidal vein with one distinct branch (tending to di^ppear 

 in mounted specimens) ; hind wings very small, bearing three stout 

 hooks at apex (PI. XIV, fig. 16). Legs long, bearing numerous hairs 

 particularly on tibia; tibia nearly twice as long as femur and nearly 

 four times as long as tarsus; tarsus two-jointed, first joint short; digitules 

 fine unknobbed hairs (PI. XIV, fig. 17). Short fine hairs scattered over 

 integument; on dorsal surface of sixth abdominal segment two groups, 

 each of fifteen pores, on the seventh segment two groups, each of twelve 

 pores (it is from these pores that the abdominal brush issues) ; style 

 short and conical, with a broad base; sexual organ as long as abdomen 

 and finely annulated (annulations showing under high power of micro- 

 scope) (PI. XIV, fig. IS). 



Xylococcus quercus Ehrh. 



Eggs. — Length .65 mm., diameter .3-4 mm.; oval, highly polished; 

 color varying from pale orange yellow to light red. 



Larva, first stage. — Length varying from .65 mm. to .75 mm., 

 diameter from .35 mm. to .40 mm. Color orange red. Shape broadly 

 oval; segments all well defined. Eyes black, situated on prominences 

 posterior and laterad to antennas (PI. XIV, fig. 19e). Antenna short, 

 stout; six-jointed; formula 6, 1, 5, 2, 4, 3; joint one stoutest; remaining 

 joints approximately equal in diameter; joints three and four without 

 hairs; hairs on joints one, two, five and six increasing in length towards 

 apex; on joint five at base of exterior lateral edge a stout spine; on joint 

 six a ring of four stout spines near the base and a single spine on the 

 apex, a very long bristle at apex; a single pore^on joint two (PL XIV, 

 fig. 19). Legs long and stout; tarsus longer than tibia; a ring of pores 

 and one long hair on trochanter; a few hairs on tibia and tarsus; digitules 

 on tarsus fine unknobbed hairs, on claw knobbed hairs (PI. XV, fig. 1). 

 Rostrum large, situated about middle of body; sucking bristles very 

 long. Anal tube protruding from body, being an extension of the outer 

 walls of two groups of chitinous spinnerets that open into the posterior 

 end of the alimentary canal. Two pairs of spiracles on thorax, eight 

 pairs on abdomen; the former inconspicuous; the latter with well 

 developed stigmatal tubes (PL XIV, fig. 3). Integument smooth and 



