134 NEW NOK'III AMERICAN ANTHOMYITDAE (dIPTERa) 



numerous short, erect, stiff, and a few Ions slender hairs. Fore tibia with 

 an antero-dorsal and two postero-ventral bristles; mid tibia with two antero- 

 dorsal bristles in addition to the same bristles as in the male; hind femur 

 with very short weak postero-ventral bristles. Costal tliorns both very 

 IdUfj;. Length, 7 to 8 mm. 



ri^yp(,__^- Bozenian, Montana, June 18, 1913, [Montana 

 Exper. Sta.]. P(tr(itijpes. — BozcMuan, Montana, July fi, 1916; 

 Waubay, South Dakota, Jiuu' (i, 1918, (Aldi'icli). T\\yor females 

 and two males. 



Mydaea occiden talis sp. n. 



.Ua/r. -Similar in eolor to jtcif/ann Fabririus. The female has the anterior 

 Iat(>ral angles of the thorax broadly testaceous yellow. 



The eyes of the male are separated at narrowest part of frons by at least 

 as great a distance as width across posterior ocelli, while in pagnna they ar(^ 

 separated by about the width of anterior ocellus. The prealar bristle is 

 nuich shorter than in pagana, and the male has no strong bristles on the sides 

 of the posterior margin of the foin-th tergite,but has two or more strong bristles 

 on each sidd of fifth sternite, which are absent in pngana. Length, male, 

 (1 mm.; female, 6.5 mm. 



Type. — cf ; Base Station, Mt. Washington, New Hampshire, 

 July 7, [Boston Soe. Nat. Hist.]. Allotype.— cf ; Bashbish Falls, 

 Massachusetts, June 27, 1912, [Illinois]. 



I have seen no North American specimens of paqcDxt. The 

 European si)e('ies tineta Zetterstedt is closely related to oecidentalif^, 

 but the male has the eyes closer, and both sexes have the hind 

 tibia with fotu- or five, instead of twoor three, antero-dorsal bristles. 

 Mydaea persimilis sp. n. 



Male and Jcinnk'. — This species along with urbnna and discimana is black, 

 slightly shining, covered with rather dense yellowish gray pruinescence, 

 has the thorax quadrivittate and the abdomen with a dorso-central black 

 vitta, and the legs yellowish testaceous. The wings in all three species are 

 yellow at bases and the cross-veins are not infuscaled. The antennae are 

 entirely black in persimilis, and all the temoi'a an> pale in the female, while 

 in the male they are largely blackened. 



Structurally this s])ecies is similar to iirbana, diifering most noticeably in 

 having the arista with short hairs, the longest of which are decidedly shorter 

 than the width of third antennal joint; the i)realar bristle is nearly half as 

 long as the bristle l)(>hind it. Fore tarsi normal in form in female; fore tibia 

 without median bristle. Fifth sternite in male with the posterior incision 

 not regularly rounded as in vrhana, the form in both sjiecies as shown in 

 figures :i and 4. Length, (') to S nim. 



Type— 9; Lake Louise, Alberta, Canada, August 15, 1908, 

 (Dr. ('. S. Minot), [Illinois]. Allotype.— d' ; Kodiak, Alaska, 



