400 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY, 
ical characters used in the descriptions should be looked upon, 
therefore, as being in the main only of supplementary value, 
supplementing coloration. I have found coloration, in spite of 
its variability, the better criterion for the separation of the species. 
The anatomical characters, nevertheless, proved very helpful. 
T. signata (Norton) and semirubra (Norton) have proved trouble- 
some, and I am not at all sure that I have accurately determined 
and delimited either. The former appears to be especially varia- 
ble, and variant 5 of the females approaches semirubra. In the 
case of semirubra, the type of which is unfortunately lost, what is 
its relation to attracta (Norton) {aitracta is a Tenthredella and not 
a Tenthredopsis, and its type which I have rediscovered is in the 
collection of the American Entomological Society) and to barn- 
stoni (W. F. Kirby)? (The type of the latter is in the British 
Museum and I have not seen it.) More material is needed, and 
this applies not only to these two speci,es but to the whole genus, 
so that a systematic examination of the genitalia of the males and 
ovipositors of the females will be possible. Both show differences, 
as I have found from the examination of isolated specimens (PI. 4, 
figs. 5, 6), and can probably be used for taxonomic purposes. 
Morice has found specific differences in the saws of Dolerus (Trans. 
Ent. Soc. London, 1913, pt. 3). Tenthredella and the Tenthre- 
dinidae as a whole are in a generalized state and care must be 
exercised in the use of characters for purposes of classification. 
The predominating colors are black, yellow, and ferruginous, 
or some shade of the last two, and these have often proved difii- 
cult to describe. The clypeus is, as a rule, and the labrum and 
the basal portion of the mandibles are invariably yellow or white, 
or some shade of these. The apical portion of the mandibles is 
ferruginous, or pale ferruginous, and the extreme apex as well as 
the inner face is black, and the ferruginous is often black or black- 
ish basally. The term mandibles refers to the broad basal por- 
tion. The palpi are as a rule of the same color as the labrum and 
basal portion of the mandibles, or slightly paler, and unless dis- 
tinctive from these, will not be mentioned in the descriptions. 
The apical portions of the bifid claws are likewise ferruginous, 
and finely margined with black. 
Owing to the diversity of the coloration, certain general descrip- 
tive color terms had to be invented. In connection with the 
