AMERICAN HYMENOPTERA. 19 



species being often described as two different species. Through the 

 kindness of those having the types of Messrs. Cresson, Ashmead and 

 Provancher in charge, I have been enabled to study the types, with 

 the exception of one or two of Provancher's, and compared them 

 carefully. I have also found specimens comparing well with de- 

 scriptions made by Walsh, and with Mr. Cresson's large collection 

 to work with, have succeeded in much the more thoroughly system- 

 atizing the tribe than could otherwise have been done. More than 

 this, most of the species were originally described from a single speci- 

 men or two of only one sex. As both sexes are now known of a 

 large share of the species (21 of the 29 ) and there was much more 

 material at hand for description, the monograph did not seem com- 

 plete without a short description of each species, which will enable 

 the determination of each sex and a more definite of the species than 

 otherwise could be. 



BASSim Grav. 

 Posterior tibise black, with broad white baud. 

 Abdomen rufous, black at base and apex ; tips of tibiae usually red. 



leetatorius Fabr. 



Abdomen black only at apex var. sycophauta \^'alsh. 



Abdomen black, with only termiual parts of segments 2, .3 and 4 rufous ; tij) 

 of tibife red, with a black annulus between the red and white. 



var. terininalis. 

 Abdomen black, marked more or less with pale spots or bands ; if middle seg- 

 ments are margined with rufous, the posterior tibise not red at tips. 



Pleurae black and yellow ... orbitalis Or. 



Pleura and sternum honey-yellow Scutellaria Cr. 



Posterior tibise white, black at tips. 



Pleura black ooneiiiiius Cr. 



Pleura in part rufous pulchripes Prov- 



Bassus Isetatorius Fabr. {Ichneumon) Syst. Piez. p. 63. 



B. tripidkras Walsh, St. Louis Acad, of Sci. iii, 85, %, '$ . 



9 . — Length 6 mm. Head, thorax, base and tip of abdomen, hind tarsi, base 

 and lower middle of hind tibise, black ; four anterior legs, posterior coxse, femora, 

 and often tips of tibise, tip of abdominal segment 1, whole of 2 and 3, and more 

 or less of 4, rufous; anterior orbits, mouth, tegulae, spot in front, line beneath, 

 cuneiform spots on mesouotum, scutellum, post-scutellum, and band on posterior 

 tibise, white. 



% . — Differs only in having the face, scape beneath and a stripe on pleura. 

 yellowish white. 



Var. st/cophanta Walsh, differs in having the basal segment of the abdomen 

 rufous ; the metathorax also is rufous sometimes in this variety. 



Var. terminalis. — For the want of a better name this dark variety may be known 

 as terminalis. It has only the terminal half of segments 2, 3 and 4 of the abdo- 

 men rufous. 



TRANS. AM. ENT. SOC. XXII. FKBRUARY, 1895. 



