ocellus at tip of the median carina. Pronotum short, tricarinate, the 

 lateral carinae curving out behind the eyes and reaching the lateral 

 margin. Scutellum typically with five complete and distinct longi- 

 tudinal carinae. Elytra longer than the abdomen, broadly rounded 

 at apex, six discal and from nine to ten apical cells. Hind tibiae 

 with three spines on basal half. 



Logotype of the genus: Oliarus walkeri (Stal). 



The shape of the male genital styles is often quite char- 

 acteristic in this genus and an aid to specific identification. 



Key to the species of Oliarus 



Elytra deep smoky brown, at least toward the apex, 1. 



Elytra pellucid or nearly so, sometimes banded or mottled with 

 brown, 2. 



1. Elytra deep smoky brown, the slender costa and stigma pale, 

 cinnamomeus Prov. 



... Elytra smoky at apex beyond the stigma, base usually subhyaline ; 

 size smaller, humilis SAY 



2. Elytral nervures distinctly punctate, 3. 



... Elytra hyaline or a little dusky at apex where the nervures are 



then heavy and brown, nervures impunctate or nearly so, 6. 



3. Frons broad, brown with an ivory white area on either margin 

 next to the base of clypeus; elytra hyaline with the stigma and 

 nervures toward their apex brown, 4. 



... Frons unicolorous, the clypeus sometimes a little paler, 5. 



4. Ventral margin of male pygofer with a long and broad median 

 tooth, roundedly expanded and feebly bilobate at apex; genital 

 styles narrow and curved at base, abruptly expanded and almost 

 square beyond the apex of the median lobe; a large species, 9 1-2 

 11 mm., :....placitus VAN D. 



... Ventral margin of male pygofer with a short, slender tooth; geni- 

 tal styles extending half their length beyond the pygofers, their 

 inner margins narrow, nearly cylindrical at base, the apical half 

 broad and obliquely truncate, together spear-shaped, pale yellow, 

 6 1-2 7 1-4 mm., aridus BALL 



... Male pygofer not described, a small species, 6 mm. difficilis VAN D. 



5. Clypeus generally paler than the frons; elytra heavily , maculated 



or generally transversely banded, stigma subquadrate, 



5-lineatus SAY 



... Clypeus scarcely paler than the frons; elytra less maculated, the 

 stigma distinctly longer than broad, vicarius WALK. 



6. Length 8 mm., elytra entirely pellucid with fuscous nervures, 

 stigma, and basal band, slossoni VAN D. 



... Length 4-5 mm., elytra nearly hyaline or somewhat infuscated 



at apex, without a basal band, franciscanus STAL. 



58 



