890 MOSQUITOES OF NOKTH AMERICA 



rather acutely triangular, central tooth prominent and stout; eight teeth on each 

 side, first five small and crowded, last three large and remote. Mandible 

 quadrangular, produced in the direction of the dentition, nearly smooth with- 

 out ; two long, smooth filaments near apex ; an outer row of cilia ; a row of long 

 sparse cilia on outer edge arising from shingle-like ridges ; dentition of three 

 long spine-like teeth, nearly separate, sessile, with a group of filamentous spines 

 at base and setae within ; process below oblique, a round lump near tip bearing 

 setae; two setse within, nearly in line with the subapical cilia; four long hairs 

 at base. Maxilla elongate ellipsoidal, truncate at base, divided by a band-shaped 

 suture; inner half hairy; a crown of hairs at tip with some feathered ones; 

 outer half with two digits on one side and a spine on the other; palpus twice as 

 long as wide, with four digits of different lengths rather well developed. 

 Thorax rounded, wider than long ; hairs abundant, the long single ones much 

 longer than width of thorax; subdorsal prothoracic tufts multiple. Abdomen 

 rather slender, anterior segments shorter; lateral tufts of first two segments 

 multiple, very short; a very long lateral hair on third to sixth segments and a 

 shorter one on seventh ; long subdorsal hairs on fourth and fifth segments and 

 shorter ones on sixth ; a small dorsal chitinous plate on sixth segment ; a very 

 large one on seventh segment covering most of dorsal aspect; a transverse plate 

 on eighth segment, excavated before the air-tube. Tracheal tubes narrow, 

 flexuous, expanded into large bladders in posterior half of thorax. Air-tube 

 small, slightly tapered, about three and a half times as long as wide ; no pecten, 

 but a large tuft before middle. Lateral comb of eighth segment a double row 

 of long bars, anterior row of twenty-two scales in a straight line, diminishing 

 to minute ones at lower end, posterior row of six much larger scales; single 

 scale of anterior row with a long tip, feathered down the sides ; of posterior row 

 much stouter, produced into a bar, the feathering at base only. Anal segment 

 about as long as wide, obliquely terminated, ringed by the plate ; dorsal tuft a 

 long hair and brush on each side; a single lateral hair; ventral brush well 

 developed, confined to barred area; anal gills short, about as long as segment, 

 broad, tapered to a point. 



Pupa (plate 149, fig. 707). — Cephalothoracic mass ovate, with small tufts an- 

 teriorly on the dorsum; air-tubes slender, slightly notched at tip. Abdomen 

 moderate, hair-tufts numerous but not long; a small multiple tuft on apical 

 angles of eighth segment ; anal paddles elongate-ovate, with a minute multiple 

 tuft at tip. 



Egg (plate 145, fig. 669). — Subcylindrical, the ends bluntly roxmded, very 

 slightly tepered toward one end ; color black ; sculpture of longitudinally elon- 

 gated hexagons; egg covered with a gelatinous membrane which overlaps con- 

 siderably on either side and forms a means of attachment, this overlapping 

 portion with many transverse ridges. 



The eggs are laid singly, on their sides, close to the water-line on the side of the 

 cavity containing the water. This is normally a hole in the trunk of a tree, 

 though water barrels and similar receptacles are occasionally made use of. Dr. 

 Dyar had some water, taken from a tree-hole, standing in the laboratory in a 

 glass vessel. Apparently during the night eggs were deposited on the glass at 

 the edge of the water-film by a mosquito that had entered the room. These 

 eggs were placed vertically in twos, threes, or singly, attached by their sides, 

 each covered with a wrinkled, veil-like membrane. They hatched in three days 

 and the larvae descended into the water. The first larval stages were rapidly 

 passed, but the development as a whole was not rapid. The larvae pupated and 

 emerged normally. Several broods no doubt succeed each other through the 

 year. The winter is apparently passed in hibernation as mature larva. Mr. 

 Busck brought larvae from St. Louis, Missouri, that he had collected late in the 

 season in a water barrel. The specimens did not pupate while kept in the 



