40 



ENTOMOLOGICAL SOCIETY 



hairs, mostly stellate. Basally a portion of the ninth abdominal seg- 

 ment is strongly constricted off into what appears to be a short, dis- 

 tinct segment; projecting over this, from the hind margin of the eighth 

 segment, like a hood, is a triangular fleshy flap with its tip prolonged 

 into a knob. Anal segment (fig. 7) elongate and slender; on each 

 side, close to the posterior margin, a very regular row of strongly 

 curved spines, about twelve in each row ; below these are the ventral 

 hooks which are short and each with two nearly equal teeth. Ventral 

 rudder of 18 or 19 long, coarse, unbranched ciliate hairs. The four 

 anal gill-flaps are rather small, elongate. Dorsally the anal segment 

 bears at its tip two long, straight, plumose setae, and curving over 

 these another pair of plumose hairs. 



Pupa. Length about 7 

 mm. Thoracic portions 

 short and globose, the ab- 

 domen long. Eyes large, 

 emarginate for the super- 

 iorly inserted antennse. The 

 trumpets large, broadest at 

 the middle and tapered to 

 the base and apex ; surface 

 coarsely reticulate ; apical 

 opening very minute. The 

 abdominal segments with 

 long, stellate, colorless, sen- 

 sory hairs at the sides near 



the posterior margin. Paddles (fig. 8) broader than long, inserted 

 well apart and directed obliquely outward; the approximating margins 

 with minute serrations. 



The pupa floats below the surface of the water and main- 

 tains itself in a perpendicular position, the abdomen extended 

 straight downward. When disturbed it darts about by strokes 

 of its abdomen with amazing rapidity. The pupa, like the 

 larva, is colorless. The air bladders of the anterior pair are 

 distinctly visible in the pupa, in the lower part of the thorax, 

 but they are not pigmented. When the larva approaches the 

 pupal period the pigment spots of the air-vesicles break into 

 irregular groups, leaving spaces between them, and the pig- 

 ment is probably removed in the process of pupation. 



FIG. 8. Sayomyia punctipennis: Tip of 

 abdomen of pupa. 



In discussing this paper, Doctor Dyar said that the food 

 habits of the Sayomyia in the open lakes were not known, 

 but that the larvae were very destructive to other mosquito 

 larvae in puddles near Washington. 



