20 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



the hypopygium of P. claviculatus : '^ " Hypopygium lon- 

 giusculum, subsessile, nigrum, lamellis fuscis, e basi latiore 

 longe attenuatis, nigro-pilosis," may be taken to indicate 

 that this species, too, presents the peculiar hairy filiform 

 appendages which arise from the bases of the lamellae in P. 

 ■flliferus and P. frofinquus. 



Medeterus Fischer. 



In his able monograph of this genus ^ Kowarz distin- 

 guishes twenty-seven European species. Only two Ameri- 

 can forms have been described hitherto, both by Loew, 

 in his Monograph of N. American Dolichopodidas — M. 

 nigrifes from a female and M. veles, from a badly pre- 

 served male specimen. Kowarz has established two sub- 

 divisions of the genus, the one comprising species with 

 four, the other species with only two scutellar bristles. 

 The latter group has been raised to the rank of a genus 

 {Oltgochcettis) by Mik.^ Mik also finds that the species 

 of this genus lack the acrostichal bristles and have only 

 three inner dorsal bristles in a row. Of the eleven new 

 species here described from the United States, nine are 

 typical Medeterus, but concerning the generic position of 

 the remaining two, I am in doubt, M. aberrans, sp. 

 nov., known to me only from a single female specimen, 

 differs from the other species to such an extent that, as 

 soon as the male is found, it will probably have to be 

 assigned to a new genus. The other doubtful species is M. 

 fetulcus, sp. nov., of which I have seen only a single male 

 specimen. It differs from other North American species 

 in having only two scutellar bristles, but as it possesses five 

 dorsal bristles in either inner row and also well developed 

 acrostichal bristles, I decline to assign it to Mik's genus, 

 which w^ould then be based on a single character — the 

 number of scutellar bristles. The difficulty is increased by 

 the fact that M. -petulcus has the front narrow and prolonged 



1 Cent. VII, 83, p. 106. 



2 Die Dipterengattuug Medeterus Fisher, Wien, 1877. 

 '^ Dipterologische Untersuchungen, 1878,- p. 7. 



