REPORT OX MOSOUITOES. i8 



tuft except in the three anterior segments ; these with three or 

 more. The eighth seg-ment bears the lateral combs ; the scales 

 composing them each with a long apical spine and short lateral 

 ones (fig. 9)-, attached to a separate band, fringe-like, six or 

 eight scales on each band, the central ones large and long, the 

 lateral ones small and broad (fig. 8). The anal siphon (fig. 7) 

 is very large, greatly dilated in the center and tapering rather 

 acutely toward the apex ; each of the lateral pectens have three or 

 four spines, the single spine (fig. 10) slender, with a broad base 

 and a number of long and short upright basal teeth, which may 

 be on one or both sides of the main spine. In small larvae the 

 siphon is proportionately much larger and is paler in color. . The 

 ninth segment is almost twice as broad as long, completely ringed 

 by the chitinized saddle and the fourteen or fifteen short tufts of 

 the ventral brush are confined exclusively to the ventral margin, 

 each issuing from a distinct pit, rather than a barred area which' 

 is present as a mere rudiment at the apex. The double dorsal 

 tuft is very small and the anal gills long and slender, a little 

 over twice the length of the anal segment. 



Habits of the Early Stages. 



"The eggs," according to Prof. Morgan, "resemble somewhat 

 in shape those of Stegoinyia fasciata, though larger. Short spines 

 pointing toward the so-called head of the egg are uniformly dis- 

 tributed over the entire shell. The egg has a flat and a con\'ex 

 surface, and with the latter uppermost presents a distinctly fusi- 

 form shape. Unless debris or a strong film floats upon the sur- 

 face 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 30th, a 

 few hatched on May 15th, others hatched May 30th. and still 

 others of the same brood on June loth. It will be seen from 

 this that a wide range obtains as to the period of incubation. 



"The larvae are active at the surface of the water for the first 

 twenty-four hours, after which they move to the bottom when 

 disturbed, and can remain there as long as forty-seven minutes 

 without coming to the surface for air. 



"The larvse are not 'wrigglers' in the true sense of the term. 

 They jerk characteristically when suddenly disturbed, but ordi- 

 narily move from the top to the bottom of the vessel at an angle 

 of about 45 degrees, with little motion save the rapid movement 

 of the oral cilia. The passing of the larvae from the top to the 

 bottom of the water with apparently little effort gives them a 



