84 AMERICAN HYMENOPTERA. 



3. Hair of thorax above without black Group J. 



(In M. heicetti Ckll.. with very few dark hairs; in dentiventris with a small 

 patch of dark hairs on sciitellum.) 

 Hair of thorax above with black (very little in hewetti and dentiventris). 



Group L. 



Group J. 



Hair of thorax above toithout hlncl:. 



Hair on inner side of basal joint of hind tarsi ferruginous 1. 



Hair on inner side of basal joint of hind tarsi black or dark fuscons. .Group K. 



1. Abdomen with four white clean-cut bands; smaller than helfraqei 'Texas). 



Tetralonfa cressoiiiana (Ckll.). 

 Abdomen with three wide clean-cut white bands on a black grouiid ; sides of 



fifth segment with white hair T. belfragei (Cress.). 



(T. lata (Prov.) is close to this, but with white bands only on segments 3 and 

 4, segment 2 being all black.) 

 Abdomen witli three wide greyish white or pale grey bands; sides of 5 with a 



light marginal patch T. cordleyi Vieieck fcf. also donata). 



Abdomen not so ornamented 2. 



2. Larger and more robust 3. 



Smaller and less robust 4. 



3. Light hair of fourth abdominal segment white. 



MelissodeN thelypodii Ckll. 

 Light hair of fourth abdominal segment pale fulvous M. hewelti Ckll. 



4. Anterior middle of scutellum with the shining surface showing, though thinly 



pubescent, posterior part and sides densely covered with fulvous hair; 



pale hair on abd. s. 2 and 3 pale ochreous .t. 



Scutellum nearly all hidden by fulvous pubescence; light hair of abdominal 

 segments 2-4 all pale ochreous or pale fulvous. 



M. aurigenia Cress. 



5. Pale hair of abd. s. 4 pale ochreous, but white on hind margin ; flagellum not 



so dark, and pleura not as in qalvestonensis M. tepaiieca Cress. 



Hair of abd. s. 4 all white; lower part of pleura in front with black hair 



(Texas) M. gaIvestoiien$«is Ckll. 



(At Fedor, Texas, May 27, 1901, Mr. Birkmann took a form of M. gahestoti- 

 ensis having the black hair on lower parts of thorax reduced, and 

 scarcely differing from tepaneca. It has the flagellum colored as in gal- 

 vestonensis, and the hair at apex of abdomen (as in type galvestonensis) is 

 perfectly black, whereas in tepaneca it is strongly suffused with red. The 

 punctures extend over much more of the metathoracic area than in 

 tepaneca.) 



NOTES. 



(1.) Tetralonia lipjnce (Ckll.) may be looked for in this group. 

 It has a subspecies semilippue, concerning which see Proc. Biol. 

 Soc. Wash., xviii, p. 179. 



(2.) Aidhedon compta (Cress.) conies in this series. Thorax 

 with dense short fulvous pubescence ; legs with dark fulvous pubes- 



