46 GEO. H. HORN, M, D. 



O. OCUlaticoUiS Say.— A slender species entirely black, clothed with 

 cinereous pubescence. Thorax with two callosities. Elytra obliquely truncate 

 at tip. 



Colorado and Northern Texas, rare. 



O. bimacnlataOliv. — Slender, black, thorax and often the cervix yellow, 

 the former usually with two callosities. 



Several varieties occur. 



var. tripunctata || Fab. — Thorax with two discal and an ante-scutellar black 

 spot. 



var. basalis Lee. — Thorax with two discal spots and entire basal margin 

 black, perspicillaia Hald., is merely a smaller form. 



■Dar. . — Thorax, often the cervix, yellow without spots. 



Our most abundant species. Occurs everywhere east of the Rocky 

 Mountains. 



O. quadricallosa Lee. — A large species with four distinct callosities on 

 the thorax. The elytra are black, with cinereous pubescence, tips subtruncate, 

 the epipleurse always pale at base. The abdomen varies in color, rarely entirely 

 rufous, usually with the last two or three segments rufous. 



California and Nevada. 



O. Sclianmii Lee. — Flavo-testaeeous. Occiput usually fuscous. Elytra 

 variable in color, tips rounded or feebly subtruncate. The legs may be entirely 

 yellow, or the tibiae and tarsi fuscous. 



var. Schaumii Lee. — Elytra brownish, epipleurse and a short lateral vitta 

 testaceous. 



var. . — Elytra in great part yellowish, an elongated triangular fuscous 



scutellar spot, and a narrow vitta from tip toward base. 



var. . — Elytra black, epipleurse pale. 



var. . — As in the preceding with the disc of the thorax entirely black. 



(May this be Saperda marginata, Fab. ?). 



The first two varieties occur in the Gulf States, the last two in 

 Illinois and Missouri. 



O. tibialiis Hald. — Black above and beneath, sparsely cinereo-pubescent, 

 anterior tibiae and femora at tips rufous. Thorax densely and rather coarsely 

 punctured and without callosities. 



I have seen but one specimen. Pennsylvania. 



O. flavipes Hald. — Linear, black above and beneath, legs yellow. 

 Middle States and Illinois, rather rare. 



O. ocellata Hald. — Moderately robust. Beneath entirely red. Thorax 

 with two callosities. Elytra black, cinereo-pubescent, epipleurse black. Legs 

 usually pale, tibise and tarsi fuscous. 



var. ocellata Hald. — Head and thorax rufous. 



