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AMERICAN MUSEUM GUIDE LEAFLETS 



hatched larva the latter regions can hardly be distinguished from each 

 other, hut as the larva grows the three fused segments of which the 

 thorax consists become enlarged and flattened. Legs are absent, but both 

 thorax and abdomen bear a great number of symmetrically placed pairs 

 of branched feather-like hairs, arranged in a manner characteristic of 

 the species. These hairs project laterally and aid in maintaining 

 . . equilibrium, but they undoubtedly serve other purposes 



•- too, being also organs of touch and possibly of respiration. 

 Similar, but smaller, hairs are found on the back of the head, and many 

 very small, simpler hairs are distributed over the whole body, particu- 



. -BRUSHES 



TEETH ON MANDIBLE 



STOUT HAIR ON MANDIBLE 



MOUTH OPENING 



•ANTENNA 



■MANDIBLE 

 MAXILLARY PALP 

 MAXILLA 



LOWER LIP 



FIG. 9. HEAD OF ANOPHELES LARVA SHOWING MOUTH-PARTS 



Ventral view. Magnification 4."> diameters. 



larly along the back and sides. On the back of the abdomen are five or 

 six pairs of dark-brown palmate structures, which float on the surface of 

 the water, when the larva is at rest, and aid in maintaining the hori- 

 zontal position of the body which is characteristic of larvae of the genus 

 Anopheles. 



The next to the last segment bears on its upper side the short 

 "siphon," which reaches the surface of the water, when the larva floats 

 in its usual position. In the siphon are the openings of the two main 

 trachea', or respiratory tubes. The larva is strictly air-breathing and 

 docs not normally remain away from the surface of the water, except 



