374 



Say^s Descriptions of 



In the insect productions, I give a new name to this spe- 



I 



cies. 



2- T. davdtus. Abdomen at base slender and a little 



nodulous ; wings at tip dusky. 



Inhab. United States. 



Body black ; head and stethidium with silvery reflec- 

 tion : wings hyaline, terminal margin dusky : ahdomen 

 clavate ; the first and second joints petioliform, a little 

 nodulous at their tips : posterior tarsi white ; the terminal 

 joint and base of the first joint black ; ^ with a spine on 

 the posterior trochanter. 



Leno;th about nine twentieths of an inch. 



Var. «. Terminal joints of the tarsi blackish ; a yellow 

 band at base of the second segment of the tergum. 



Judging from memory, as in the preceding instance, I 

 suppose this to be the fuscipennis , Beauvois, but not that 

 of Fabricius, for the reasons there adduced. I may also 

 state that this species does not correspond with Fabricius' 

 description in having " alae nigrae cyaneo parum nitidae," 

 neither does it agree with " Pedes nigri tarsis albis" inas- 

 much as the posterior pair only are partially white. 



3- T. carindtus. $ Black ; head and stethidium with 

 silvery reflection : a prominent, acute carina between the 

 antennae, divaricating above the antennae into two carinae : 

 antenn<£ emarginate beneath towards the middle : wings 

 hyaline ; a slight tint of dusky at tip : tergum gradually 

 attenuated to the base ; three fii-st incisures a little con- 

 tracted : feet^ anterior pair of knees, tibiae and tarsi yel- 

 lowish ; intermediate knees and tarsi yellowish, the latter 

 in the middle above dusky ; posterior tarsi obscurely yel- 

 lowish towards the tip. 



Inhab. Indiana. 



Length three tenths of an inch. 



K' 



1 



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