iQio.] S. P. James : The Indian Anophelinte. 103 



and do not form tufts. Thorax with the dorsum clothed with hairs 

 and narrow, sharp-pointed scales like those in the genus Myzomyia. 

 Prothoracic lobes with a dense tuft of broad true scales projecting 

 anteriorly. Head with short very broadly expanding upright forked 

 scales. 



Type species of the genus, barbirostris. Van der Wulp. The 

 generic characters are shown in Plate xii. The other species in 

 the genus are sinensis, Wiedmann, nigerrimus, James and Liston, 

 and nigerrimus , Giles. 



Genus 10. CHRISTOPHERSIA, nov. gen. Abdomen with the 

 dorsum of each segment thickly clothed with hairs and lanceolate and 

 blunt-ended scales which are not aggregated together to form tufts of 

 any kind. The ventral surface of each segment is devoid of scales 

 except that from the apices of six segments in the mid line prominent 

 tufts of long, blunt-ended scales project directly downwards. These 

 tufts resemble the single abdominal tuft present in the genus Myzor- 

 HYNCHUS Thorax clothed with rather narrow lanceolate and blunt- 

 ended true scales. Prothoracic lobes with a prominent tuft of true 

 scales. Head with the usual kind of upright forked scales. 



Type of the genus: halli, James. The generic characters are 

 shown in Plate xii. 



It only remains now to summarize in tabular form the essen- 

 tial differences between the groups I have defined, to indicate 

 briefly how to place an anopheline in its correct genus, and to show 

 in the form of a table the changes made in the generic position of 

 the different Indian species. 



How to ascertain the generic position of an anopheline. 

 (i) Using a microscope with a two- thirds inch objective and a 

 high power eyepiece (No. 8 or No. 12), examine the dorsal, lateral, 

 and ventral surfaces of the abdomen of the mosquito. If scales 

 are not immediately seen search carefully the last segment and 

 the genital processes. Upon the decision whether the abdomen 

 carries scales or not depends the accuracy of the subsequent 

 determination. The decision is always very easily made, l)ut 

 especial care should l)e taken to examine the lateral and ventral 

 aspects of the abdomen as well as the dorsal aspect. If no scales 

 are present, the mosquito belongs to one of the first four genera. 

 (2) In that case next examine the head. It will be seen at once 

 whether the upright forked scales are of the usual broadly expand- 

 ing type (all the spotted- winged anophelines have scales of this type) 

 or whether the upright forked scales are very narrow in their whole 

 length (linear or rod-shaped). If they are rod-shaped the mosquito 

 belongs to the genus Neostethupheles. (3) If the upright forked 

 scales are of the usual broadly expanding type , next examine the 

 prothoracic lobes from the dorsal asi)ect. To see one of them clear- 

 ly slant the pin so that the mosquito is turned more or less on its 

 side. A very little practice will overcome any initial difficulty 



