C 51 ] 
the postef ior margins of the segments fed dark honey yel- 
low ; venter somewhat piceous. 
Length less than one fifth of an inch. 
Taken on the wing at twilight, in October. 
TACHINUS, Grav. 
1. T. atricaudatus^l^oh. 
Is very closely allied to atricapillns, &cinctiis, Grav. 
2. T. obsoletus^ Black ; thorax, curve on the elytra, seg- 
ment margins & feet yellowish. 
Inhab. Virginia. 
Body black : mitenncv fuscous ; four basal joints yel- 
lowish ; tip of the last joint dirty fulvous ; mouth honey 
yellow : /Aoma: honey-yellow : e/j/Zm, in some lights with 
an appearance of obsolete strise ; subsutural impressed line 
obvious ; a honey-yellow base, suture & terminal margin ; 
abdomen with the segments piceous on their posterior 
margins : feet pale yellowish. 
Length over one fourth of an inch. 
I obtained this species in October, at Chinquotege 
Island. 
3. T. trimaculatus, yellownsh ; head & three elytral spots 
blackish : tergum rufous. . 
Inhab. Pennsylvania. 
Body yellow, tinged with honey-yellow : head obscure 
piceous ; antennce. fuscous : four basal joints pale yellow ; 
mouth yellow : mandibles piceous at tip : /Aoma: immacu- 
late : scutel piceous ; elytra with a few remote punctures 
on the basal half, & towards the tip obsolete impressed 
strise, a subsutural impressed line, near which isa series of 
distant larger punctures ; region ofthescutel with a dilated 
blackish triangle, extending to the middle of the length of 
the suture & thence by a narrow h paler sutural line to 
the tip; exterior margin or epipleura black, with a spot near 
its tip extending inwards, half way to the suture but not 
reaching the tip of tbe elytra : tergum dull sangineoiis : 
near the tip with an obsolete, blackish band ; at tip with 
a yellowish tinge. 
Length over three twentieths of an inch. 
4. T. cmctieollis^ Black ; posterior thoracic margin, 
line of the elytra & feet yellowish. 
