64 Bulletin American Museum of Natural History [Vol. XLII 



Labium not attaining the distal end of the stipes; submentum extremely trans- 

 verse, short, joint-like; mentum somewhat cordiform, its upper surface with numer- 

 ous short spines and a seta in each externo-frontal angle; palpiger shorter than sub- 

 mentum and with sides rounded; first segment of palpus short; second segment about 

 three times as long and possessing several slender apical setae ; ligula well developed, 

 slender and almost twice the first palpal segment in length. 



Prothorax with sides slightly rounded, of the same width as the head ; pronotum 

 well chitinized except at anterior and posterior margins; sagittal line present and 

 continuing throughout the thorax ; prosternum Avith two large sclerites in front of the 

 coxae touching along the median line. Meso- and metathorax slightly wider than 

 prothorax but about one-half as short; mesonotum with fairly well-developed sclerites 

 divided in front by a horizontal suture and with four slightly chitinized square areas 

 at its posterior margin. Pro-mesotergal and meso-metatergal conjunctiva with two 

 very narrow sclerites. Sclerites of metanotum very irregular, each with a widely 

 separated posterior projection. Episterna and epipleura are cushion-like lobes. 



Legs fairly long, about twice as long as the thorax is wide; coxae transverse, a 

 little longer than the femora; tibiae slightly shorter than the latter but much longer 

 than the well-developed claw-like tarsi, which bear two inner setae set side by side. 

 The anterior coxae a little, the middle more, and the posterior widely separated. 



Abdomen with eight distinct segments and very slightly narrowed posteriorly; 

 ninth and tenth segments rudimentary. The first seven tergites similar and separated 

 by a conspicuous intersegmental membrane; each of the former has three transverse 

 folds, while the latter has only two. The first tergite bears two pairs of small, chitin- 

 ized patches, the anterior very small and usually covered by the metathorax. Epi- 

 sternites and epipleurites similar to the thoracic ones and are cushion-like lobes. 

 Lateral lobes of intersegmental membranes single and not double as in Philydrus. 

 The second fold of each of the first seven segments bears a transverse row of four in- 

 conspicuous tubercles, the inner pair more prominent with a small chitinous ring at 

 its base. The tubercles each bear a colorless seta. The sternites have folds corres- 

 ponding to those of the tergites but have no chitinized areas. The eighth tergite 

 represents the superior valve of the stigmatic atrium and bears a large plate which is 

 wider than long. The posterior margin of the latter is nearly straight, its sides are 

 rounded and its anterior margin only slightly emarginate. The posterior margin of 

 the superior valve is four-lobed, each lobe with a seta. The atrium closely resembles 

 that of Cymbiodyta. 



Full-grown Larva. — Length. 8 mm. ; width at the mesothorax, 1.27 mm. Gray 

 colored or dirty white except chestnut-brown chitinized areas. Head, dorsally, 0.6 mm. 

 long and 0.69 mm. wide. Labro-clypeus is more oblique. The first segment of the an- 

 tennae has become more elongate and now is longer than the second segment, the anten- 

 nal lobe is slightly shorter and less prominent. Mandibles are very blunt and have lost 

 their serrations. Mentum with the seta in each externo-frontal angle prominent as well 

 as each medio-lateral one. Prothorax enlarged slightly posteriorly. Body increases 

 in width gradually as far as the second abdominal segment and then decreases. 



Pupa. — Length, 5.2 mm.; width at its thorax, 2.16 mm. Whitish. Head smooth 

 and bears two supraorbital styli on each side. 



Pronotum smooth, its anterior and posterior margins straight, the latter very 

 slightly emarginate in the middle. The styli are arranged as follows: ten at the 

 lateral and anterior margins, two of which are at the middle of the anterior margins ; 



