392 BULLETIN 45, UNITED STATES NATIONAL MUSEUM. 



Abdomen pointcd-ovjito, the jietiole rather long, fluted; the seeond 

 segment occupies the greater i)art of its surface, with sulci at base; 

 the apical joint pointed, stylus-like. 



Legs rather long, pilose, the femora davate, the ])osterior tarsi a little 

 longer than the tibia>, or fully as long, the basal Joint one-third longer 

 than the secon«l. 



The gen\is is snflRcientlj' «listrnc+ from the other genera with 13- 

 jointed antenuic by the length of the submarginal vein, the absence of 

 a basal nervure, the more pointed abdomen, the seeond segment with 

 sulci at base, and by the antenna! characters of the male. 



I am not aware that anything has been published respecting the 

 habits of the genus, but if my memory serves me rightly I saw speci- 

 mens of P. rnjipcs Westw. in the IJerlin Museuni,reare<lfrom Eristalis 

 tenax, along with Diapria conivti. 



Our species seem to be quite distinct from the described European 

 species, and may be recognized by the aid of the following table: 



TABLE OF SPEriES. 



FEMALES. 



Wings subliyaliiie or tiii|H«Ml with fuscous 2 



Wiuf^shyaliiio. 

 Antcniiii' boiiey-yellow or lirownish-yellow, clavate-moniliform. 

 Flagelhim twice as loug as the scape, the 5 or (J teriuiual joints fuscous or 

 black, the last enlarged, fusiform, more than thrice as large as 

 as the penultimate; legslirowuish-yellow; abdomen entirely 



black 1'. PARViLi's, sp. nov. 



Flagellnm elongated, the last joint only black, globose-ovate; legs honey- 

 yellow. 

 Mesonotal furrows complete; abdomen pale at base.. .P. terminatus Say. 

 Mesonotal furrows wanting; abdomen not pale at base. .P. ilavipes Ashra. 

 Antenna' fuscous or black. 

 Flagellnm 2.V times as long as the scape, the last joint fusiform, about thrice 

 as large as the penultimate; legs pale reddish, all coxa' black, 



the femora dusky P. ltahensis, sp. nov. 



2. AntenuiP and legs reddish-yellow. 

 Last four joints of antenna' black. 



Scutellum with two foveai at base; scapube with a grooved line. 



P. sriNosu.s, sp. nov. 

 Scutellum nnifoveate, the fovea creuulate; scapube without a groove. 



P. PALLIDIPE8, sp. nov. 

 .MALES. 



Wings fusco-hyaline. . , . . _ , -• 



Legs, including coXic, pale brownish-yellow; anfenn.'e pale ferruginorte. 

 Pedicel and the first funiclar joints of an equal length, the joints beyond 

 slightly more than 4 times as long as thick. 



Pedicel a little shorter but stouter than the first funiclar joint, the joints be- 

 yond very long, several times longer than thick. 



P. SPiNoSfs, sp. nov. 

 Wings dark, fuscous. • 



Legs ferruginous, all coxa; and the swollen portion of femora black, the tibiai 



toward apex issore or less fuscous; antennae black, the pedicel 



shorter than the first funiclar joint. .P. oregonensis, sp. uov. 



