AQUATIC INSECTS IN NEW YORK STATE 441 



mandible just above tlie lateral Tine, one pair below this one 

 and a little ceplialad; another pair about one fourth of the 

 length of the head caudad of these but \jing as far below the 

 lateral line as the first is above. Directly caudad of the first, 

 but midway between the front and hind margin of the head, 

 is another. Close to the dorsal suture, one fourth the length 

 of the head cephalad of the caudal margin, is still another; and 

 finally there is a single one on each side at the base of the 

 labium [fig.lO]. 



The ventral surface of the labrum is shown in figure 9. The 

 liypopharynx resembles that shown in plate 50, figure 5; and 

 the maxilla that shown in figure 6. The epipharynx is as shown 

 on plate 48, figure 9e, its free end having four to six filaments, 

 the apical pair being stoutest. This member may be bent for- 

 ward and the filaments then spread out, fanlike. The " jointed 

 appendages" [fig.9;] are well developed; each is apically expanded 

 into a handlike process with seven or eight " fingers." These 

 appendages are attached at a point near the anterior margin 

 of the labrum. The mandibles [flg.l2] have each five blunt teeth, 

 a fringe of coarse branched hairs projecting mesad,and two stout 

 setae on the dorsal surface near the base. The labium [fig.lO] 

 possesses about 19 blunt teeth, no suture being visible between 

 it and the lateral (or ventral?) sclerite. The antennae are of 

 moderate length [fig.ll] and bare, with three terminal, jointed 

 appendages. The thoracic and abdominal feet are as on plate 

 5U, figures 7 and 12; but the abdominal legs appear a little 

 longer in proportion to their diameter. The entire body of the 

 hi'rva is almost devoid of hairs excepting the caudal tuft. 



Pupa [fig.l3]. The pupa is of a fuscous color with a greenish 

 tinge; its thorax is apparently without either tracheal gills or 

 breathing tube. On the dorsal posterior margins of each of the 

 abdominal segments excepting the first and last there are 10 to 

 12 short, stout, caudad projecting teeth, the two or three lying 

 nearest the lateral margin being smaller than those more dor- 

 sad; and on the ventral posterior margin of the abdominal 

 segments excepting the first, second and last there are six or 

 eight stout teeth projecting cephalad. At the anal end of the 

 last segment are three pairs of short hollow filaments, which 

 may have a respiratory function. The length of pupal life is 

 about two days. 



This pupa greatly resembles that of D i a m e s a c u i i - 

 c i d e s as figured by Heeger in Sitzb. d. k. Akad. d. Wiss. 

 Wien., 1853, excepting that in the latter there are eight caudal 

 filaments instead of six. 



Described from specimens taken in Cascadilla creek, Ithaca 

 N. Y., April 1902. 



