j |4 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



4. Ischnodemus macer, new species 



Allied to pracultus, a little longer with shorter rostrum 

 and black sericeous venter; black, basal three segments of 

 antennae, rostrum and legs f ulvo-testaceous ; elytra short, 

 fuscous with pale costa and membrane. Length 4-6 mm. 



Antennae but little shorter than median line of head and pronotum together; 

 segment I little longer than wide, attaining apex of tylus; II as long as 

 anterior width of pronotum; III a little shorter than II, fusiform. Rostrum 

 arched in all specimens before me but apparently reaching nearly to anterior 

 coxae; segment IV not longer than II: anterior femora more expanded than 

 in falicus, its inner margin ciliate and armed at apical fourth with a short 

 sharp tooth. Pronotum with a broad transverse minutely punctured area 

 before the hind margin and an obvious sulcate median line on the anterior 

 lobe. Elytra abbreviated, tip of corium attaining apex of first tergal segment; 

 membrane ovate, reaching to middle of second segment, veins obscure. 



Color, black, nearly opaque, clothed with minute sericeous scale-like pubes- 

 cence and some longer gray hairs; hind margin of pronotum sometimes 

 tinged with castaneous; antennae, rostrum and legs f ulvo-testaceous or at times 

 almost castaneous; apical segment of antennae black; elytra fuscous with 

 costa pale yellowish and membrane white; connexival margins faintly 

 castaneous. 



Described from one male and two female examples taken 

 by Mr. A. Koebele at Nogales, Arizona, September, 1906. 

 In my own collection is one male taken by the late Prof. 

 F. H. Snow on the Santa Rita Mountains, Arizona, which 

 differs only in having the hind margin of the pronotum 

 castaneous. This specimen was listed by me as pracultus 

 Dist. ?, in 1909 (Can. Ent., xli, p. 375) but it undoubtedly 

 is distinct and specifically identical with those described 

 above. 



Holotype, male, No. 754, and allotype, female, No. 755, 

 Mus. Calif. Acad. Sci. Paratype in Koebele collection. 



Type locality, Nogales, Arizona. 



5. Plinthisus martini, new species 



Minute, piceous or black, moderately polished; hind mar- 

 gin of pronotum castaneous; antennae at base, rostrum and 

 legs, honey-yellow; brachypterous elytra truncate, with the 

 corium and clavus connate, the latter confused punctate. 

 Length scant 2 mm. 



Head two-thirds as wide across the eyes as basal width of pronotum ; 

 eyes small, contiguous to pronotum; rostrum slender, attaining hind margin 

 of metasternum ; segment I attaining base of head, II and III subequal, each 



