Entomology of the Illinois River. 205- 



Pupa. —Length 13 ram., exclusive of respiratory- 

 tube, diameter of abdomen 1.6 mm., thorax scarcely 

 broader; abdomen depressed, with prominent margins. 

 Dark chestnut-brown, wings and thorax blackish, sides 

 of abdomen paler, covered with an opaque ochraceous 

 crust when dry, shining above and on appendages where 

 denuded. 



Head with a row of four minute setiferous tubercles 

 &bo"\'S antennae. Prothorax anteriorly with a pair of 

 proriect cylindrical respiratory tubes, finely annulated, 

 about 2.5 mm. long, sinuate, and darker and a little 

 thicker at base, outer portions parallel and contiguous 

 in fact, about as in luteipennis ; median line above 

 them strongly carina te. Mesothorax nearly smooth; 

 wing-pads ending at apex of second abdominal; tarsi side 

 by side, with joints and tips evenly in line, latter at 

 apex of third segment. 



Abdomen not barred, anterior divisions of the second 

 to the seventh abdominals with two dorsal folds, each 

 with a pair of small sharp teeth; posterior divisions 

 with a similar pair of teeth on the anterior and posterior 

 margins, the latter pair included in a close-set row of 

 minute teeth. Beneath, except under the wing-pads, these 

 segments show the same structure, except that the ante- 

 rior division has three folds, the teeth of the middle fold 

 nearest together. The lateral margins are rather sharp,, 

 and bear four sharp teeth, one opposite each set of dis- 

 cal teeth. 



Penultimate segment very short, armed with two pairs 

 of dorsal teeth and a prominent lateral tooth, beneath 

 smooth; last segment with three elongate conical re- 

 curved projections nearly as long as the preceding seg- 

 ment, an upper pair and a shorter cleft one below, all 

 closely contiguous. 



The abdominal sculpture is quite distinct from that of 

 the pupa of luteipennis. 



