36 



N. E. McINDOO 



The wings have dorsal and ventral surfaces, and the legs may 

 be divided for description into two surfaces. The inner surface 

 faces the body of the insect and the outer surface is directed 

 away from it. On the specimen examined, four groups of pores, 

 besides many scattered pores, were found on each front wing; 

 three groups, besides several scattered pores, on each hind ^\dng ; 

 and four groups, besides two isolated pores on each leg. 



Fig. 1 Wings of silkworm moth, Bombyx mori 9 , showing location of groups 

 of olfactory pores as indicated by the numbers 1 to 7, and disposition of scat- 

 tered pores on the veins as represented by dots, X 3. A and B, dorsal and ven- 

 tral surfaces of right front wing respectively; and C and D, dorsal and ventral 

 surfaces of right hind wing respectively. 1 to S A, first to third anal veins; C, 

 costa; cl to 2, first and second cubital veins; M, media; ml to S, first to third 

 medial veins; R, radius; rl to 5, first to fifth radial veins; Sc, subcosta. 



For descriptive purposes in locating the olfactory pores on 

 the wings, the veins at the bases of the wings may be called 

 costa (fig. 1 A-D, C), subcosta (Sc), radius (R), me(^ia (M), 

 and anal vein (1 to 3 A) ; the names, given by Comstock (manual, 

 '01) to the distal ends of these veins, are also appended, so that 

 no confusion may arise. The groups and scattered pores are 

 located as follows: Groups nos. 1 to 7 lie on the bases of the 

 wings, nos. 1 to 4 being on the front wing and nos. 5 to 7 on the 

 hind wing; nos. 1, 2, 3, 5 and 6 are found on the dorsal surfaces 

 while nos. 4 and 7 lie on the ventral surfaces. Nos. 1 to 3 (fig. 



