THE LEAD-CABLE BORER IN CALIFORNIA, 51 



Sutures: Distinct frontal sutures obliterated. Epicranial suture concealed by 

 prothorax when head is in natural position, three tiines as long as width of 

 clypeus; anterior two-thirds of suture (es, PI. II, Fig. 17) dorsal, posterior 

 one-third {es, PI. II, Fig. 19) ventral, situated on recurved hind part of cranium, 



Clypeus (PI. II, Fig. 28): Oval, transverse; one-third as wide as cranial 

 capsule, one-third as long as wide, slightly chitinized on each side of median 

 oval part which is pure white ; posterior margin of chitinized parts densely 

 set with fine, light setae about as long as length of clypeus. 



Lahrum (PI. II, Figs. 28, 31) : Transverse, obovate, with each posterior corner 

 Invaginated forming a slender chitinous process ; entire width of labrum to 

 width of cranial capsule as 1 : 4 ; length to width about as 1 : 3 ; slightly chitin- 

 ized ; disk divided by two parallel, longitudinal, straight bands into three 

 divisions ; median division somewhat larger than each lateral ; entire anterior 

 margin and the lateriil divisions densely set with well developed, slightly 

 pendent, brown setae, about half as long as length of labrum. 



Antenna (PI. II, Fig. 28) : About as long as length of clypeus. three-jointed, 

 borne by large, conical basal skin. Basal joint cylindrical, about one-third 

 the length of entire antenna ; as wide as long. Second joint cylindrical, some- 

 what longer and narrower than basal joint. Apical joint conical, a little shorter 

 than basal joint, half as wide as long. Corresponding to a supplementary 

 joint, a small round spot ventrally near foot of apical joint. Basal joint anteri- 

 orly with a few short setae ; apical joint with single minute seta at the tip 

 and a minute seta at the base. 



Mandibles (PI. II, Figs. 23-26) : Strong, short, about one-fourth the length 

 of cranial capsule ; cuneate, with inner and outer surfaces subtetragonal, dorsal 

 and ventral surfaces subtriangular ; length, depth, and width almost equal. 

 Inner surface apically with transverse cavity, about four times broader than 

 long, anteriorly and laterally limited by sharp, thin, perlucid, slightly rounded 

 edge, posteriorly gradually sloping down into median portion of inner surface. 

 Median portion about twice as long as apical portion, transverse, sub- 

 trapezoidal, flat, longitudinally rugose. Posterior portion of inner surface 

 transverse, about as long as apical and median together ; outline irregularly 

 rounded, disk with a few large, low lobes and with a large, globular, chitinous 

 protuberance on side of the interior wall (PI. II, Fig. 24, showing a longitudi- 

 nal section of inner wall of mandible). Margin below posterior portion thick, 

 heavily chitinized ; projecting into the mandibular internal cavity ; carrying a 

 little trapeze-like process. Exterior, dorsal, and ventral mandibular surfaces 

 smooth and shiny. Fossa and condyle large. Color of mandible black, base 

 reddish brown ; no setse. 



Maxilla (PI. II, Figs. 27, 29) : Outer lobe of mala (galea?) cushionlike, with 

 round outline and somewhat flattened, about twice as large as palpiger (pg) ; 

 dorsally (PI. II, Fig. 20) and ventrally hairy, with several large setse. Inner 

 lobe (lacinia?) ventrally enforced and almost completely represented by a 

 slender chitinization, twice as long as outer lobe and almost as long as stipes, 

 anteriorly not reaching far beyond base of outer lobe, posteriorly reaching 

 chitinization along inner margin of stipes ; anterior half of chitinization of 

 inner lobe stylus shaped ; posterior half heavier and C-shaped. Stipes fleshy 

 and about as large as the lobes and palpiger together; along inner margin with 

 thin, light chitinous band which is broadest and strongest posteriorly where 

 cardo hinges ; fine, long setae from antero-external surface. Maxillary palp 

 slightly projecting beyond exterior maxillary lobe ; two-jointed, borne by large, 

 jointlilve palpiger. Palpiger somewhat smaller than outer lobe; at base with 

 chitinous setose half ring; at top on ventral surface with transverse series of 

 setse. Palpus as long as palpiger and about half as long as antenna; basal 

 joint almost as long as thick, with a few minute setse; apical joint as long, 

 half as thick as basal joint, with small tactile papillae oh top (compare PI. I, 

 Fig. 5). Cardo (c. PL II, Fig. 27) rhomboidal, flat, chitinized; vertically 

 placed against ventral surface of stipes ; when at rest, concealed (PI. II, Figs. 

 19 and 29). 



Maxillary articulating area (ma, PI. II, Figs. 29 and 19) : Fleshy, almost as 

 large as mala, connecting stipes and submentum. 



Submentum (sni. PI. II, Fig. 29) : About as long as stipes; transverse, para- 

 bolic, twice as wide as long (PL II, Fig. 19), fleshy. 



Mentum {ni, PL II, Figs. 29 and 19) : As long as submentum, not much wider 

 than long; free, fleshy. 



Stipes labii (stl, PI. II, Fig. 29) : Transverse, elongate, oval; length to width 

 as 1:4; width to width of mentum as 4:5. Separated from mentum by a 



