402 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Characters Leading to Tenthredella. 
The following characters leading from the suborder Chalasto- 
gastra (or Tenthredinoidea) have been taken by the writer from 
the table given by Doctor Enslin in " Die Tenthredinoidea Mittel- 
europas" (Deutsch. Ent. Zeitschr., Beiheft, Dec, 1912). The dis- 
tinction between Tenthredella and Tenthredo L., however, is the 
writer's own and is designed merely for the separation of the 
species of the two genera as found in the geographical area to 
which he has limited himself (see History of Tenthredella) . The 
distinction between the two as given here might perhaps be criti- 
cised on the score that it is not absolutely positive, but this is 
owing to the fact that the two genera, the Nearctic species at 
least, do not seem to be clearly defined. In the opinion of the 
writer, the true relation between these two genera, as they occur 
in North America at least, is yet to be determined. Mr. S. A. 
Rohwer of the United States National Museum gives a classifica- 
tion of the Chalastogastra in the Proceedings of the Entomological 
Society of Washington (vol. 13, p. 215, 1911), but it is only to 
tribes. 
Anterior wings with at least three (four) cubital cells ; antennae 
have their origin above the clypeus and between the eyes; a free 
and visible ovipositor sheath present ; the genitalia in the male in 
part visible at the apex of the abdomen; first abdominal tergum 
longitudinally divided; anterior tibiae wdth two strongly devel- 
oped apical spines or spurs; pronotum deeply semicircularly 
emarginate behind; basal vein meets the subcostal considerably 
before or basal to the point of origin of the cubital vein ; antennae 
with more than four (nine) segments and not capitate; radial cell 
divided by a cross-vein; lanceolate cell not petiolated; basal vein 
parallel with the first recurrent vein; hind coxae not elongated, 
the apices of the hind femora not reaching to the apex of the 
abdomen; inner margins of the eyes strongly convergent ventrally 
and reaching rather close to the clypeus. 
Inner and upper margins of the antennal sockets strongly upraised and, as a 
rule, extending backward more or less as longitudinal ridges defining laterally 
a depressed median area; antennae usuallj' long and slender and, as a rule, 
much longer than, or as long as, the head and thorax together (taken from the 
anteriormost portion of the eye to the posterior margin of the meta-episternum) 
and not, or scarcely, thickened before the apex; species usually elongate and 
