HYMENOPTERA 333 



which therefore have a closed submarginal cell; ovipositor either saw-like or a 

 sturdy borer, never thread-like or capable of being coiled within the body. p. 338 



Chalastogastra 



BB. Antenna; inserted below the eyes immediately above the mandibles under 

 a transverse ridge, their bases concealed; front wings with the transverse part 

 of vein M 2 wanting; vein R 4 in the hind wings wanting, therefore no closed 

 submarginal cells; ovipositor thread-like and coiled within the mesothorax. 



p. 343 Idiogastra 



AA. Base of the abdomen constricted into a narrow pedicel, p. 345. . . .Clistogastra 



TABLE FOR DETERMINING THE FAMILIES OF THE 

 CHALASTOGASTRA 



A. Front wings with three marginal cells, both vein R and R 2 being present; the 

 basal segments of the flagellum are consolidated, thus forming what appears to 

 be a very long third segment, and the remaining segments are small. 



XyelidcB* 



A A. Front wings with the free part of vein R 2 always wanting; antennae with three 

 or more segments, third segment never as long as all the following segments 

 together; if the third segment be long, antennas, consisting of only three seg- 

 ments. 

 B. Front wings with subcosta present as a distinct longitudinal vein. p. 339 



Pamphiliid^e 



BB. Front wings with subcosta absent; rarely it is present as a pale, very in- 

 distinct line, closely appressed to vein R + M, or vein Sci may be present as a 

 transverse vein. 

 C. Radial cross-vein (r) of the front wings received by the 2nd submarginal 

 cell (R&) or if it is absent or the 2nd and 3rd submarginal cells united 

 (R4 united with R 5 ), then the anterior tibiae have a single apical spur. 

 D. Front wings with the cross-vein m-cu subequal in length to the first section 

 of the free part of media. 

 E. Vein Sci absent in the front wings; the last abdominal segment bears a 

 more or less horn-like prolongation; maxillary palpi one-segmented; 

 labial palpi two- or three-segmented, the last segment enlarged and 

 bearing a large sensory cup, the first segment not elongate, p. 339 



SlRICID^E 



EE. Vein Sci present; last abdominal segment without horn-like pro- 

 longation; maxillary palpi four-segmented; labial palpi three-seg- 

 mented, the last without a sense-cup, the first elongate. Xiphydriida 

 DD. Front wings with the cross-vein m-cu joined to vein M at or near its 



separation from vein R. p. 340 Cephid^e 



CC. Radial cross-vein (r) of the front wings received by the 3rd or 4th submargi- 

 nal cell (cell R4 or R3) or wanting; anterior tibiae always with two apical 

 spurs. 

 D. Abdomen with distinct pleural sclerites; bearing the spiracles, antennae 



clavate. p. 341 Cimbicid^e 



DD. Abdomen without separate pleural sclerites; antennae not clavate in 

 North American forms, p. 342 TenthrediniDjE 



TABLE OF FAMILIES OF THE CLISTOGASTRA f 



A. With well-developed wings. 



B. Hind wings without an anal lobe.t 



C. No erect scale or node between the gaster and the propodeum. 



* The families in italics are not discussed in the text. 



f This table of families of the North American Clistogastra is compiled from a 

 table of the families of the Clistogastra of the world prepared by Professor J. Chester 

 Bradley. 



t In the hind wings of the insects belonging under this category neither the second 

 anal furrow nor the axillary excision is present, but there is sometimes present a weak 

 preaxillary excision, more rarely (some genera of Braconidae) a pronounced notch, but 

 never forming a deep slit. See also footnote on page 335. 



