OF NATURAL HISTORY. 7 1 .'J 



transver.se, dilated, deeply indented groove at base of the 

 scutel, having small rai.sed lines within, which are not very ob- 

 viou.s : wings hyaline : nervure of the radial cellule obsolfte at 

 base; second cubital cellule destitute of the exterior nervure : 

 stigma triangular, fuscous : tergum oblong-oval, punctured, gla- 

 brous, and polished at tip; ba.sil segment rather rough, the 

 lateral edge a little elevated and dull yellowish ; venter each side, 

 excepting at tip,didl yellowish : oviduct not exserted beyond the 

 tip of the abdomen : feet honey-yellow, tips of the j)osterior 

 thighs above slightly blackish. 



Length nearly one-tenth of an inch. 



It resembles the insiyrr very much in its markings, but the 

 oviduct is not exserted. (Ireat numbers are deposited together, 

 and they ultimately spin their cocoons and envelope them with 

 an exquisitely fine silky substance, which has been called '* ani- 

 mal cotton." 



4. M. CONGREOATA. — Black ; thorax destitute of obliiiue, lined 

 sutures; abdomen elongate, subfusiform. 

 Inhabits I'ennsylvania. 



^Body black : mandibles and palpi white : thorax destitute of 

 oblitjue, lined sutures; transverse suture at the base of the scutel 

 dilated, profound : wings hyaline ; radial cellule with the ner- 

 vure as obvious as the others; second cubital cellule rounded de- 

 stitute of the exterior [263] nervure ; apical nervures obsolete: 

 stigma triangular, fuscous : abdomen oblong, subfusiform, more 

 polished than the thorax; first and second joints densely punc- 

 tured or minutely lineated ; the first joint pedunculiform, ar- 

 cuated, narrower than the second : venter along the middle pale 

 yellowish : feet honey-yellow : posterior tibiae at tip and posterior 

 tarsi dusky. 



Length over one-tenth of an inch. 



llesembles mr/lipnt, hut the thorax has not the oblique, lincatod 

 grooves, and the abdomen is more elongated and slender at base. 

 This basal segment, like that of the mcllipes, has a slight tubercle 

 on each side- 

 In June, 1822, I obtained eighty-four individuals of this spe- 

 cies from the larva of a Sphynjr. 

 1835.] 



