a Family of the Hymcnoj)tcra Heterogyna. 201 



Sp. 5. Lab. Swainsonii, Shuck. Length 6^ lines ; 



Expansion 13 lines. 

 Rufo-teslaceus, pubescens, capite (mandibiilis antennhqut; exceptis) cas- 



taneo : pedunculo abdominis transverso-quadrato si/pra subconvexo ; 



pedibus brevis. 



Body of a pale reddish testaceous. Head, with the exception of the man- 

 dibles and antenna!, of a bright castaneous ; the carincs of the face, 

 behind which the antennae are inserted, very prominent, and termi- 

 nating gradually in front of the anterior ocellus; the ocelli placed in a 

 curved line on the vertex : the antennae having the flagellum at the 

 base, as stout as the scape, which is a little less than one-fourth the 

 length of the organ : mandibles long and very slender, leaving a largo 

 semicircular space between them and the clypeus. 



Thorax in front and scutelkim very gibbous ; metathorax perpendicular and 

 slightly produced laterally : superior wings with their nervures and 

 stigma pale testaceous : the marginal cell lanceolate, slightly acumi- 

 nated beyond the second submarginal, the first of the latter narrow, 

 pentagonal, less than the second, from which it is separated by a waved 

 nervure : the second also narrow, but growing more so towards its apex, 

 where it is separated by a short straight nervure from the following ; it 

 is much less than the marginal cell, and has the recurrent nervure in- 

 serted about its middle, beyond which to the apex of this cell the cu- 

 bital nervure is considerably thickened: legs short and slender. 



Abdomen slightly shining, its peduncle transverse-quadrate, with the angles 

 rounded, the surface plane, except towards its apex, where it has a slight 

 convex transverse ridge, and is as wide as the second segment, its 

 ventral portion slightly produced; the base of all the segments very 

 slighth' constricted, and the extreme apex of the terminal one consi- 

 derably compressed vertically, where it has a deep fissure : the male 

 sexual organ protruding beneath, in the form of a deeply and con- 

 cavely emarginated plate, the lateral processes of which form acutely 

 acuminated slightly upcurved spines. 



In my own collection. 



This insect was captured by Mr. Swainson in the Brazils, to 

 whose entomological exertions there we are indebted for the know- 

 ledge of several undescribed species, and this I accordingly dedicate 

 to him. It is distinguished from the preceding by many particulars, 

 but most obviously by the relative proportions of the marginal and 

 first and second submarginal cells. 



[To be continued.] 



Ann, Nat. Hist. Vol.5. No. 30. May \M0. 



