io8 Records of the Indian Museum. [Vol. IV, 



sharp-pointed, and very narrow, it belongs to the genus Nyssomv- 

 zomyia. 



Hints, (i) When beginning the study of classification by 

 scale ornamentation always select good, unrubbed specimens. II" 

 mosquitoes bred from larvae are being used do not kill them until 12 

 hours have elapsed from the time when the}- hatched out. The 

 best specimens are those which, bred under favourable conditions 

 from larvae, have been allowed one meal of blood and then kept 

 in suitable jars until the meal has been digested. (2) Do not use 

 card-discs for mounting the mosquitoes to be used in studying 

 this subject. Cut off the head of the fine silver pin and mount 

 the mosquito on the pin so that an equal length of the pin pro- 

 jects from the dorsum and from the venter. Then stick either the 

 point or the head end of the pin into a small block of pith or of 

 cork. For examination, the mosquito can now be pinned with 

 the dorsal, ventral, or lateral surface uppermost and a proper 

 view obtained. When card-discs are used this cannot be done, 

 because the disc is alwa^^s in the way and hides the part one 

 desires to examine. (3) A knowledge of whether the scales are 

 false scales or true scales is not necessary for determining the 

 genus, but if it is desired to study this matter thoroughly, the 

 scales must be mounted fiat on a slide and examined with a high 

 power objective. It is essential to carry out the same procedure 

 when it is desired to study thoroughly the shape of various scales. 

 (I refer of course to a closer stud}^ than is necessary for ascertain- 

 ing whether the upright forked scales of the head are rod-shaped 

 or broadly expanding, whether the thoracic scales are sharp- 

 pointed and ver}' narrow or blunt-ended and broad, etc.). The 

 following is the simplest method of obtaining the particular scales 

 one wishes to study. Dissect out with a sharp knife the part of 

 the mosquito that carries the scales and place it on a slide under 

 a cover-glass. Tap and press the cover-glass slighth^, then remove 

 it and slide the part of the mosquito away with the point of a 

 needle. Replace the cover-glass and fix it with strips of gummed 

 paper. Many scales will have remained on the slide during these 

 manipulations. Examine them with a iV inch oil immersion lens 

 and draw them with the aid of an eyepiece camera lucida. (4) In 

 describing the shapes of scales it would be of great advantage if 

 all observers were to adopt the exact nomenclature used b}' 

 botanists in describing the shapes of leaves. This nomenclature is 

 given in all the elementary books on botany and is very applicable 

 to the shapes of scales. The botanical terms acicular, linear, 

 oblong, elliptical, rotundate, orbicular, lanceolate, ovate, oblan- 

 ceolate, obovate, spatulate, etc., have a definite meaning and 

 significance. ''Lanceolate" is a botanical term commonl}^ used 

 by entomologists, but it is used b}^ them indifferently for scales of 

 very various shapes ; a lanceolate leaf is broadest at the base and 

 scales with that character are seldom or never seen, though oblan- 

 ceolate scales are very common. The use of such terms as " slight- 

 ly lanceolate," " long and narrow," "large and inflated," etc., 



