MOSQUITO BIOLOGY 211 



whitish at base, becoming brown apically; surface thickly set with 

 broad spines of which bases prolonged, giving antenna scaled appear- 

 ance; tuft situated on curve at middle, consists of six or eight hairs; 

 apex has three long spines, one very short one and small joint. Rotary 

 mouth brushes large, wholly composed of simple hair. Mentum broadly 

 triangular with large apical tooth and thirteen to fifteen small ones on 

 each side. Maxillary palpus normal with short, stout basal joint, man- 

 dible peculiar by deep indentation on dorsal surface, by reduction in 

 size of one of curved dorsal spines and by having row of papillae in- 

 stead of spines between large dorsal spines and teeth. 



Thorax broader than long with lateral hair tufts short and wholly 

 destitute of tufts on anterior margin. 



First three abdominal segments transversely oblong, remainder sub- 

 quadrate, each with two hairs to lateral tuft except in three anterior 

 segments ; these with three or more. Eighth segment bears lateral 

 combs ; scales composing them each with a long apical spine and short 

 lateral ones attached to separate band, fringe-like, six or eight scales on 

 each band, central ones large and long, lateral ones small and broad. 

 Anal siphon very large, greatly dilated in center, tapering rather 

 acutely toward apex ; each of lateral pectens have three or four spines, 

 single spine slender, with broad base and number of long and short up- 

 right basal teeth, on one or both sides of main spine. In small larvae 

 siphon proportionately much larger and paler. Ninth segment almost 

 twice as broad as long, completely ringed by chitinized saddle ; fourteen 

 or fifteen short tufts of ventral brush confined exclusively to ven- 

 tral margin, each issuing from distinct pit, rather than barred area, 

 which is present as mere rudiment at apex. Double dorsal tuft very 

 small, anal gills long and slender, not over twice length of anal segment. 



HABITS OF THE EARLY STAGES 



"The eggs," according to Professor Morgan, "resemble somewhat in 

 shape those of Aedes aegypti though larger. Short spines pointing to- 

 ward the so-called head of the egg are uniformly distributed over the 

 entire shell. The egg has a flat and a convex surface, and with the latter 

 uppermost presents a distinctly fusiform shape. Unless debris or a 

 strong film floats upon the surface of the water, all the eggs sink to the 

 bottom of the vessel, which accounts, no doubt, for the irregular periods 

 of incubation. Of the forty eggs deposited during the night of April 30, 

 a few hatched on May 15, others hatched May 30, and still others of 

 the same brood on June 10. It will be seen from this that a wide rangp 

 obtains as to the period of incubation. 



