SMULYAN: NEW ENGLAND TENTHREDELLA. 403 
rather slender; body very often ferruginous, or with ferruginous 
Tenthredella Rohwer, 
Inner and upper margins of the antennal sockets not, or only shghtly, up- 
raised, and the depressed median area absent or only shghtly indicated; an- 
tennae as a rule as long as, or shorter than, the head and thorax together and 
very often distinctly thickened before the apex; species robust or compact; 
body black and yellow (the yellow may not be fully developed rarely, and 
appears reddish) Tenthredo Linnaeus. 
Table of Species. 
The writer has experienced some difficulty in making out this 
table, owing to the variation in color and especially to variations 
in the shades of the particular colors. The more important varia- 
tions are noted, but, in general, the colors as given must be inter- 
preted broadly, for it was found practically impossible to take 
cognizance of every rare and slight variation and still have a satis- 
factory table. The point to be emphasized in this connection is 
that it is not the shade of a particular color which is important in 
marking the species, but the distribution of that color, or the color 
pattern. It has been the aim to incorporate these minor but 
troublesome exceptions in the descriptions which must after all 
be considered the court of last resort. 
Table for the Separation of the Females. 
(The general term pale signifies any color not black.) 
1. Abdominal dorsum black 2. 
Abdominal dorsum in part pale 12. 
Abdominal dorsum entirely pale; if with narrow transverse bands of 
black, then the antennae in part black 24. 
2. Apical segmetits of antennae white, or yellowish white 3. 
Apical segments of antennae not white 4. 
3. Meso-episternum markedly roughened; mesoscutellum as a rule in part 
white, and as a rule strongly convex; abdomen as a rule blue black 
grandis (Norton), p. 408. 
Meso-episternum smooth; mesoscutellum black and but slightly convex; 
legs in part dark ferruginous. . .nigricollis (W. F. Kirby), p. 411. 
4. Head above clyjDeus and lower margin of eye black, or only slightly 
pale 5. 
Head above clypeus and lower margin of eye with considerable 
pale 10. 
5. Pectus, and mesoi)lcura in part i)ale ferruginous G. 
Pectus and mesopleura not ferruginous 7. 
