ENTOMOLOGY. 769 



The adult of Anopheles quadriniaculatu'^ is readily distinguished from 

 species of Culex by the attitude of the body when at rest, the position 

 being- such as to keep the body in a straight line, whatever the angle 

 made with the substratum may be, and the note of the female which is 

 lower in tone than that of species of Culex. The eggs of Anopheles 

 are laid in a loose mass floating upon the surface of the water, each 

 Qgg lying upon its side instead of standing upon its end as in the case 

 of Ciilex. They are not firmly attached together. The larva of A. 

 quadrlmacidatiis remains habitualh' at the surface of the water. Its 

 breathing tube is shorter than that of Culex and its body is held 

 parallel to the surface. The natural food of the larvae consists of 

 spores of Alga?, minute sticks, and bits of cast larval skins. In the 

 final larval stage of this species the diameter of the thorax becomes 

 much greater than in previous stages as compared with the rest of the 

 body. The generation studied by the author occupied 3 days in the 

 Qgg stage, 16 days in the larval stage, and 5 days in the pupal stage, 

 making a total period of 21 days in the earlier stages. Natural breeding 

 grounds for this species were found in Maryland, Virginia, and the 

 District of Columbia. Three species of this genus have been recog- 

 nized in the United States, A. (jvadrimacidatus^ A. punctipennis, and 

 A. crucians. Brief notes are also presented on the genera Psorophora, 

 Megarhinus, and ^des. 



The natural enemies of mosquitoes are the larv?e of dragon flies and 

 the larvae of Dytiscidae, H^^drophilida?, and Gyrinidw, beside fish, 

 nig'hthawks, whippoorwills, bats, etc. 



Of the artificial remedies for use in houses the best results have been 

 obtained by burning pyrethrum powder, and catching mosquitoes on 

 the walls in kerosene cups, in cases where screening and mosquito bars 

 do not successf ull}' keep out all the mosquitoes. In the destruction of 

 larvae in breeding places, the use of a kerosene film upon the surface 

 of stagnant pools is again recommended. Permanganate of potash 

 which was heralded in the newspapers as a certain remedy for mosquito 

 larvw, is thoroughly discredited by experiments. Tar and its com- 

 pounds have also been recommended, but experiments indicated them 

 to be rather unsatisfactory as compared with the heavier grades of 

 kerosene. The planting of eucalyptus trees in the neighborhood of 

 houses seems to have the effect of keeping the mosquitoes away. The 

 most eflicient remedy, however, for the mosquito nuisance is the 

 thorough drainage of all pools in which the larv^ee breed. 



On the resting position of Anopheles, L. W. Sambox and G. C. 

 Low {British Med. Jour., 1900, Xo. 2077, p>. 1158).— T\iq authors 

 made extended observations on the habits of Anopheles claviyer, which 

 is said to be the most common species of this genus in Italy. It is 

 maintained that previous statements that standing on its head is a com- 

 mon resting position of this species is incorrect. Species of Culex 



