HESPERIOIDEA OF AMERICA 97 



Genus MASTOR Godman & Salvin 

 Mastor G. & S., Biol. Cent.-Am., Rhop. n, 567, 1900. Type Mas- 

 tor anubis G. & S. 

 ? Megistias G. & S., op. cit. 571. Type Hesperia tripunctata 

 Latr. 



Palpi upturned; third joint small. Antennae slightly more 

 than one-half as long as primaries in male, less in female ; apieu- 

 lus shorter than thickness of club and variously reflexed; club 

 short, rather stout. Costa of primaries flattened; outer margin 

 slightly rounded ; apex somewhat produced. Secondaries broad- 

 ly rounded, relatively small ; in the female the primaries are less 

 produced and the apex of the secondaries more prominent than 

 in the male, much as in Atrytone. The male possesses a small 

 stigma made up of a dot of scales below vein 2 and a longer) 

 patch above, variably developed in different specimens. It is 

 much larger in bellus than in phylace, very small in oslari and 

 absent in fusca. Cell of primaries normal ; vein 5 slightly 

 curved, arising a little nearer to 4 than to 6. Mid tibiae with a 

 few spines. Fig. 28. 



I believe that oslari is more closely related to A. nanno than 

 to bellus, and am placing fusca in this genus rather doubtfully. 

 Unfortunately I have not had sufficient material for dissection 

 in this group and have therefore been unable to make a careful 

 study of the anatomy of the doubtful species. I am unable to 

 find a good basis of separation for fusca, which Godman and 

 Salvin say belongs in Megistias, but I am not familiar with 

 tripunctata so Megistias may not fall before Mastor. 



Key to the species 



1. Vestiture of head and fringes golden bellus 



Head golden ; fringes whitish phylace 



Without golden vestiture 2 



2. Under surface powdery gray oslari 



More or less yellowish below, never powdery gray fusca 



1. MASTOR FUSCA 



Hesperia fusca G. & E., Trans. Am. Ent. Soc. I, 2, 1867. 



Southern United States, New Jersey, Pennsylvania; April to July. St. 

 Louis, Mo., (Knetzger). 



Fusca is usually immaculate grayish fuscous above and slightly tinged 

 with yellowish below, especially on the veins of the secondaries. Occasion- 



