NO. 2033. GAD-PLtES OF THE OENUS STIBA80MA—KNAB. 409 



ing the difference to be sexual, referred it to theotsenia. Lutz states 

 that he possesses many females which agree with this male in colora- 

 tion, and therefore indicated a distinct species. The third antennal 

 joint, in addition to the long dorsal process, shows an obtuse tooth on 

 the lower side, although it is less marked than in the new species 

 described below. Williston's specimen, which is before me, is from 

 Chapada, in the interior of Brazil; Lutz records the species from Rio 

 de Janeiro, Sao Paulo, and Santa Catharina. 



As other species of Stibasoma show great variation in the coloration 

 of the body vestiture, it is possible that willistonii is only a color 

 variant of theotsenia. A comparison of structures, such as the shape 

 of the antennae, should decide this point. 



STIBASOMA THEOT^NIA (Wiedemann). 



Tabanus theotsenia Wiedemann, Aussereurop. zweifl. Ins., vol. 1, 1828, p. 136. 



Stibasoma theotsenia Schiner, Reise d. Novara, Dipt., 1868, p. 94. 



Stibasoma ihiotaenia Lutz, Centralbl. Bakt., Abt. I, Orig., vol. 44, 1907, p. 143. 



Lutz states that he possesses a male which differs from the female 

 only in the sexual characters. Unknown to me. Reported from 

 Brazil and Montevideo. 



STIBASOMA FLAVISTIGMA Hine, 

 Stibasoma flavistigma Hine, Ohio Nat., vol. 12, 1912, p. 516. 

 Described from a female collected in Vera Cruz, Mexico. Unknown 

 to me. 



STIBASOMA MALLOPHOROIDES (Walker). 



Tabanus mallophoroides Walker, Trans. Ent. Soc. Lond., n. ser., vol. 4, 1857, 

 p. 123. 



This species is unknown to me in nature, but its position is obvious 

 from the description. Walker mentions not only the short stout body, 

 but also the long process of the third antennal joint and the ciUation 

 of the tibiae. Furthermore, he states: "AlUed to T. festivus, Wied." 

 Amazon region. 



STIBASOMA FESTIVUS (Wiedemann). 



Tabanus festivus ^Yi^nEMANN, Aussereurop. zweifl. Ins., vol. 1, 1828, p. 135. 

 Tabanus festivus Williston, Kans. Univ. Quart., vol. 3, 1895, p. 195. 



Through the courtesy of the American Museum of Natural History, 

 I have before me Professor Williston's specimen, and, although the 

 antermse are broken, there can be no doubt that it is a typical Stiba- 

 soma. The specimen, a female, agrees in every respect with Wiede- 

 mann's description, except that the ciliation on the outer side of the 

 hind tibiae is yellow instead of snow-white, as indicated by Wiede- 

 mann. The specimen is from Chapada, Brazil. 



