TWENTY-FIFTH ANNUAL MEETING. 133 



eral years in succession. It is more destructive on high prairie land than low land, 

 in dry seasons than in wet seasons. On the bottom farms mentioned, the damage 

 was in spots where the soil was exceptionally loose. No artificial remedies have 

 been used in this vicinity. 



ON THE HOKSE FLIES OF NEW MEXICO AND ARIZONA. 



BY O. H. TTLEE TOWNSEND, NEW MEXICO AGEIOULTTJEAL COLLEGE, LAS OBUOES, N. M. 



Horseflies rarely occur on the higher lands or mesas of New Mexico and Arizona, 

 so far as my experience goes, unless in proximity to some swale, spring, or body of 

 water. They are met with in valleys of rivers and streams, and some species occur 

 very abundantly in the neighborhood of isolated swales or marshy places filled with 

 a growth of tall grass or various plants. Such swales occur at long distances from 

 each other in some parts of this region, as in eastern-central Arizona, and may or 

 may not be situated near to a creek or spring. They are usually filled with the car- 

 casses of dead cattle, which have been unfortunate enough to get mired in them, and 

 in such cases yield a most offensive odor. 



This distribution of the horse flies is the result of the nature of the country, where 

 water holes and springs are few and far between. It is quite possible that most of 

 the species breed in these swales, but doubtless the prime reason for their occurrence 

 near water is because the animals whose blood they suck are to be found there only. 



The following species have been collected by the writer in this region: 



Chrysops fulvaster 0. S. S 2 



Silvius quadrivittatus Say. S 2 



Apatolestes comastes Will. $ 



Diachlorus gultatuliis n. sp. 2 



Tabamts imnctifer 0. S. S 2 



Tabanus lineola Fab. ^2 



? Tabanus vivax O. S. 2 



Below are given notes and descriptions of the species: 



Chrysops fulvaster Osten Sacken. — Seven 5 specimens and one S from G bar 

 ranch, Zuni river, Arizona, July 27 (Apache county). One 2 from Pescado, N. M., 

 July 31 (Valencia county). One 2 from Springerville, Ariz., June 24 (Apache 

 county). Seven 22 from Seneca ranch, north of Springerville, Ariz., June 25 

 (Apache county). Most of my 2 specimens are 8 mm. in length; the one ^ is 7 mm. 

 In the 5 the "'subhyaline elongated spot at the distal end of both basal cells," men- 

 tioned in Osten Sacken's description, extends into and occupies the central third of 

 the anal cell. There is also present the subhyaline spot in the middle of the fifth 

 posterior cell, as in the 2; and the crescent-shaped space toward the apex of the 

 wings, mentioned by Osten Sacken, also present in the 2. The discal cell is faintly 

 subhyaline in its central portion. With these exceptions, the wing of the S is wholly 

 blackish, if we except a minute subhyaline spot in the extreme proximal end of the 

 first basal cell. Osten Sacken does not mention the antennae, which are wholly black 

 in the S, but blackish with the first joint fulvous or reddish in the 2. Williston has 

 noticed the swollen first antennal joint, peculiar to this species (Trans. Kas. Acad. 

 Sci., vol. X, p. 134 ). This species is very annoying to man and horses. It was found 

 very abundantly at a slough near the Seneca ranch, about a half mile south; the 

 slough grassy, and full of reeds and dead cattle. The flies were very bloodthirsty. 

 One was found piercing one of the leather girth straps of my saddle, and another at- 



