ART. 21. XORTH AMERICAN SAWFLY LARVAE MIDDLETON. 15 



armed on the apical margin with 12-13 bristles; labium with pal- 

 piger and 2- jointed palpus. Thorax : The tergum consists of areas A, 

 B, C, and D ; A, except in the prothorax, B and C are haired sparsely; 

 A prothorax bare and constricted, D bare and narrow; mesothorax 

 and metathorax with enlarged alar area which is sparsely haired and 

 not well separated from preepipleurite ; pleurum; preepipleurite 

 large and sparsely haired ; postepipleurite of moderate size and bare ; 

 prehypopleurite triangular, of heavy chitin and sparsely haired; 

 posthypopleurite large and sparsely haired; legs with 4 joints and 

 an apical claw, joint 3 with soft pad on inner side at apex. Abdomen : 

 The tergum of urites 1-9, inclusive, is composed of areas A, B, C, 

 and D; A, B, and C are sparsely haired and D is bare and narrow 

 and urite 10 consists of an epiproct, which is sparsely haired and pos- 

 cesses pseudocerci at caudad laterad extremities ; urites 1-8, inclusive, 

 with spiracle in the spiracular area but urites 9 and 10 have both the 

 spiracle and the spiracular area wanting; urites 1-8, inclusive, with 

 the alar area distinct, bilobed and sparsely haired, urite 9 with the 

 alar area not distinct and urite 10 with the alar area wanting; 

 pleurum ; urites 1-7, inclusive, with preepipleurite distinct and sepa- 

 rate from postepipleurite and both sparsely haired, urite 8 with pre- 

 epipleurite indistinctly separated from postepipleurite and both 

 sparsely haired, urite 9 with preepipleurite indistinguishably united 

 with postepipleurite and sparsely haired, and urite 10 with epipleurite 

 not recognizable ; urites 2-7, inclusive, with hypopleurite distinct and 

 not divided into prehypopleurite and posthypopleurite. and urites 1, 

 8, 9, and 10 with hypopleurite indistinct or wanting; urites 2-7, inclu- 

 sive, with well-developed uropods, urites 1, 8, and 9 with uropods want- 

 ing and urite 10 with postpedes and with a rather prominent post- 

 callus (fold below anus). 



Color. — Head: Black; the epistoma, labrum, maxillae, and labium 

 are pale yellow with some brown ; the antennal membrane is pale. 

 Thorax : The prothorax is pale yellow, excepting the brownish neck 

 plates and sometimes the spiracular area has faint dark markings; 

 the mesothorax is pale yellow, with a brownish-black transverse 

 band, broken middorsally and extending down B across the an- 

 terior portion of the alar area and the preepipleurite and terminating 

 on the lateroventral extremities of the first and second sternal folds; 

 the metathorax is the same. Abdomen : Urite 1 is pale with a brown- 

 ish black, transverse band which is broken middorsally and extends 

 down B and across the spiracular area to, and terminating on, the 

 anterior portion of preepipleurite; urites 2-8 are similar, but with 

 the band not terminating on the preepipleurite but extending across 

 the venter on the second, or first and second, sternal areas of eaeh 



