26 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ii4 



Specimens examined.— 196. 

 Distribution. — 



United States: hawaii: Oahu: Pohakea Pass, Schofield Plateau; Hawaii: 

 Kona, Kealakekua. 



Mexico: Mexico, d.f. hidalgo: Jacala. veracruz: Jalapa, Cordoba, Ori- 

 zaba, south of Veracruz, Banderilla. 



Guatemala: Senahu (Alta Verapaz), Capetillo. 



El Salvador: Monte Cristo. 



Costa Rica: Meseta (central Costa Rica), Aurora Farm (Estrella Valley), 

 La Carpintera, Coronado, San Jose, Coliblanco, Tablaco, Zarzero, Turrialba, 

 Volcdn Irazii. 



Panama: Volcdn Chiriqui, Boquete (Chiriqui Province), Bambito (Chiriqul 

 Province), Bugaba. 



Biology. — Taken in numbers in sparse woods near Jacala, Mexico, 

 in cow and horse dung. Burrows in clay soil were 4 to 8 inches deep. 



Remarks. — Say's description of 0. incensus was published post- 

 humously in the Boston Journal of Natural History for May 1835. 

 The holotype female (pi. 1) is in the Museum of Comparative Zoology 

 at Harvard; it is in fair condition but lacks mouth parts, pygidium, 

 and part of the legs. The pronotum of the type specimen is a very 

 dark green, with reddish-brown lateral spots below the fovea and with 

 narrowly reddish-brown anterior margin opposite the head area be- 

 tween the eyes ; the carinae of the head and the pronotal prominence 

 are faintly but distinctly coppery; the elytra are dark blue-black. 

 The narrow brownish anterior margin of the pronotum is found in 

 other Mexican specimens also. The clypeal carina is noticeably 

 higher at middle. 



The cephahc horns in fully developed males are only rarely com- 

 pletely connected basally and then by a low sweUing or obtuse carina, 

 straight across from one to the other. In batesi the connecting carina 

 is nearly always present even in the male minors, curves arcuately 

 from one horn to the other, and is sharply ridged on top. 



This species which is very closely related to batesi, new species, 

 has not been taken in mainland United States but has been intro- 

 duced into Hawaii. It was introduced in 1923 by H. T. Osborn from 

 material collected at Morelos, Mexico, to assist in control of the horn- 

 fly, Siphona iritans (Linnaeus), and was recovered on the island of 

 Hawaii in 1934 and on Oahu in 1940 (see Swezey, 1935; 1940). 



Some females of curvicornis Latreille from Colombia are super- 

 ficially almost identical with incensus Say; however, curvicornis is 

 usually larger and the fully developed male pronotal protuberance 

 extends forward in a sharply pointed but somewhat flattened cone. 

 Females of 0. acuminatus Harold also resemble those of incensus 

 and batesi but are much smaller. The male clypeus in acuminatum 

 anteriorly is pointed. 0. nitidor Bates is slightly smaller and is a 



