Mar., 1922 alaskan diptera of the family syrphid^ 145 



reaching the lateral margin, third pair of spots on the fourth segment 

 similar to those on the third, outer angle produced very narrowly over 

 the margin, posterior margin of fourth segment, anterior and posterior 

 margins of fifth segment and all of sixth segment, yellow. Length, 

 11 to 13 mm. 



Female: Front black on the u]jper three-fourths, the lower half of 

 the black color yellowish pollinose, less densely so at middle, front 

 black pilose, pilosity continuing below the antennae on either side next 

 the eyes, much of the face sparsely yellow pilose; all the legs yellow to 

 the bases of the femora, coxas and trochanters dark, posterior feet pale 

 brownish. All the abdominal spots much attenuated and reaching over 

 the abdominal margins, fifth segment yellow with a curved black band 

 about half the width of the segment. 



Male: Vertical triangle black and black pilose, frontal triangle 

 black on superior half and entirely black pilose, pilosity extending much 

 below the antennas at the sides next the eyes; cheeks blackish beneath 

 the eyes, margin of the mouth behind yellow; legs to the basal fourth 

 of the femora, black, otherwise yellow with the exception of the tibiae 

 which are partially brown, the hind ones nearly black. Fifth abdominal 

 segment yellow with a very narrow median black marking. Genital 

 segment all yellow. 



Male type taken at Savonosky, Naknek Lake, Alaska, 

 July, 1919. Allotype with the same data. Paratypes, ten 

 males and seven females with the same data, a male from the 

 same locality taken in August and a female from Katmai, 

 Alaska, 1917. In the Ohio State University Collection. 



The species varies somewhat. In some specimens the 

 abdominal spots are larger and reach the lateral margins 

 plainly and at greater width than in the type. In one specimen 

 the narrow outer margin of the abdomen is all yellow and the 

 black marking on the fifth abdominal segment varies in size 

 and shape in different individuals. Sometimes the hind 

 femora of the male practically entirely yellow. The pair of 

 spots on the fourth abdominal segment is connected occasionally 

 at the anterior inner corners, forming a band which is very 

 deeply notched posteriorly. It is a large robust species, 

 easily separated from others of its size by abdominal markings. 



Syrphus curtiis n. sp. 

 Male and female: Eyes naked, cheeks, mouth margin and facial 

 stripe extending upward just over the tubercle, black; remainder of 

 face yellow. Antenna largely black, only the inferior margin of the 

 third segment reddish. Thorax yellow pilose, scutellum pale; wings 

 hyaline. Abdomen with three pairs of yellow spots entirely separated 

 from the margins of the segments, posterior margins of fourth and fifth 



