1917] Pacific Coast Species of Xylococcus 157 



joints five to eight sub-equal; joint nine slender; on joints one and two 

 hairs scattered, on joints three to eight arranged in a fringe at anterior 

 edge and increasing in length towards apex of antenna; terminal joint 

 bearing a ring of four stout spines, two long hairs and a numiber of shorter 

 hairs; on joint two a group of pores varying in number (PI. XV, fig. 3). 

 Legs very stout; tibia twice as long as tarsus; trochanter bearing two 

 long, a number of shorter hairs and a group of pores varying in number; 

 digitules on tarsus and on claw fine unknobbed hairs (PI. XV, fig. 4). 

 Rostrum wanting. Anal tube represented by an infolding of body wall, 

 not strongly chitinised. Two pairs of spiracles on thorax and eight 

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

 developed stigmatal tubes bearing two rows of pores in constriction. 

 Integument covered with short hairs, most numerous on dorsal and 

 lateral areas, and on ventral surface of abdomen arranged in transverse 

 rows segmentally; pores of two types (PI. XV, fig. 5) thickly scattered 

 over cephalic and thoracic areas, and on abdomen arranged in trans- 

 verse bands segmentally, the bands on dorsal surface being broader 

 and more dense than those on ventral surface; around vaginal opening 

 pores become more numerous; smaller type of pore predominates. 



Male, second stage. — Not found. 



Male, third stage. — Similar to stage three of female, but longer and 

 more slender. Pores on body less numerous than on stage three of 

 fem.ale; six posterior abdominal segm.ents strongly chitinised. 



Male, fourth stage.- — Length 2 mm., breadth 1.3 mm. Color deep 

 red; legs and antennae yellow. Shape oblong, broadest in thoracic 

 region; head and thorax together longer than abdomen; segments all 

 well defined. Eyes small, black, situated laterad to antennae. Antennae 

 rather short and stout; nine-jointed; formula 1, 2, 9, 3, 7, (4, 8), 6, 5; 

 joints one to three stoutest; joints four to eight sub-equal; joint nine 

 slender; hairs on each joint increasing in length towards apex, on joints 

 three to eight forming a fringe at anterior extremity; a few spines as 

 well as hairs borne on terminal segment; on joint two a group of pores 

 varying in nimiber (PI. XV, fig. 6). Legs well developed, bearing many 

 stout hairs; tibia twice as long as tarsus; trochanter with one long hair 

 and a group of pores varying in number; digitules on tarsus and on 

 claw fine unknobbed hairs (PI. XV, fig. 7). 'Rostrum wanting. Anal 

 tube wanting. Two pairs of spiracles on thorax and eight pairs on 

 abdomen; the former inconspicuous, the latter with well developed 

 stigmatal tubes with one row of pores in constriction. Integum.ent 

 covered with microscopic short, sharp hairs, stouter and more numerous 

 on posterior segments; long stout hairs and pores of one type (PI. XV, 

 fig. 8) thickly scattered over cephalic area; on thorax and abdomen 

 these are less numerous and are arranged in bands segmentally; hairs 

 increasing in number and size posteriorly. 



Male, fifth stage, pupa. — Cast skin. Length about 2 mm., breadth 

 about 1 mm. Color of abdomen deep red; thorax, legs and antennae 

 yellow; in dried specim.ens pigment is broken up, causing a spotted 

 appearance (PI. XIII, fig. 7). Shape rather broad and short; head and 



