16 BULLETIN 45, UNITED STATES NATIONAL MUSEUM. 



point being- surrounded by stiff liairs; outwardly tUe surface is convex 

 and smooth, except at about two-thirds its length, Avhere there is a tutt 

 of long liairs. At 1> the same parts are shown as viewed from beneath, 

 together with other parts not visible from above; tts, the upper sheath; 

 Is, the lower sheath; }>, penis; jx', peual daspers, the outer nmrgin of 

 which arc fringed with several long spines or hooks; bl, swollen basal 

 lobes, to which the upper and h)wer sheaths are attached. All these 

 organs, except the tips of the upper and lower sheaths, when not in 

 use, are withdrawn within the apical abdominal segments and are only 

 visible when exserted. The swollen basal lobes (hi) and the peual 

 claspers {pc) seem not to have been noticed before, and I believe are 

 now pointed out for the first time. 



Fig. 11 represents the male genitalia of Troctotrypes caudatiis Say, 

 as seen from the side after the removal of tlie left ventral spine: vs, 

 right ventral spine; us, upper sheath, slender and clavate; Is, lower 

 sheath, very broad and flat and terminating in four chitinous lobes. 



Fig. 12 represents the same organs in the male of Scleroderma ci/Iin- 

 drica, after West wood: «s, upper sheaths, "the extremities of which 

 are thin and incurved"; Is, lower sheaths, "broad and each with a 

 broad, simple stipes [dd), and four terminal lobes (f), two of which are 

 setose at the tips, and one at least more rigid than the other parts." 



In Fig. 13, PI. I, I represent the ovipositor of Scleroderma epliippium^ 

 after Westwood. In his explanation he says: 



The parts of the ovipositor itself are vertically compressed, the recurved bases of 

 the spicula" (c), Avith their muscular angulated lohe or catch {ff), beiug represented 

 as flattened. Wy strong protrusion of the spicula^ beyond the extremity of terebra, 

 the curved basal portions of the former are straightened and brought forward to 

 the base of the terebra, where their dilated angular form prevents tlicm from further 

 protrusion. The parts nuirked e. e. are the meml)raiu)us plates connecting the base 

 of the spicuhc and of the terebra itself with the interior of the abdomen. 



HABITS OF THE PERFECT INSECTS. 



The imagos are most frequently found wherever their hosts are most 

 plentiful and their lives are of short duration, seldom extending l)eyond 

 a few days. Those I have kept in confinement live but four or five 

 days, altliough in freedom they i)robably live longer. 



The favorite resorts for diapriids, bethylids, and proctotrypids are 

 low, moist places, where there is a luxuriant growth of vegetation and 

 a black or mucky soil, the decaying vegetation affording excellent food 

 for their hosts— dipterous and other larva>. The opening buds and 

 newly formed leaves of plants and trees, and especially along the out- 

 skirts of a dense forest or wood, are particularly attractive to platygas- 

 terids and teleiiomids, while the bethylids, dryinids, and scelionids, as 

 a rule, frequent the more «pen fields. In Florida, dry sandy knolls, 

 where the scrub oak grows, are the ftivorite resort of the bethylids. 

 Species in the genera Epyris and Mesitius, I have taken most frequently 



