10 DONALDSON BODINE. 



diameter. Rising from the floor is a chitinous cone about 3 vi. in 

 diameter at the base and 6 m. high. The apex is somewhat atten- 

 uate and is open. The nerv^ous apparatus is much like that in the 

 first type of sense-hair. It is broader at the apical part and passes 

 directly into the cone, filling the broad base. Sometimes two, or 

 even three of these pits are grown together. In such cases there is 

 a reduplication of all parts. Among the butterflies they are much 

 deeper, and are supplied with stiff* guarding projections from the 

 walls, Fig. 17. The cone, also, is smaller in diameter at the base, and 

 is almost or quite rod-like in form. In at least some cases, e. g. 

 Pijramels eardni, there is a circle of stiff* points around the base of 

 the cone. Hauser* describes such a bristle circle in Vanessa io. 

 Kraepelin and Raland,t however, from the study of diff*erent species, 

 dispute the existence of such a structure. Pits have a wide distri- 

 bution throughout the whole order. They are found for the most 

 part on the ventral surfaces both of the shaft and of the pectina- 

 tions. In the butterflies they are most numerous on the club. Hauser 

 says they are not limited to the two terminal segments alone, as 

 Lespes has declared, but are spread over the whole club. In Van- 

 essa atalanta I have found them in all but the three proximal seg- 

 ments of the clavola. 



5. Short projections which have become so thick as to lose their 

 character of hairs, and which in many cases have a covering con- 

 tinuous with the general integument of the segments ; Fig. 20, 5, 

 represents the form of these cones and shows their relation to the 

 segment. Fig. 18 represents a section of one from a male (h/lo- 

 samia promethea. The nerve apparatus resembles that of the rods 

 in the pits described under 4. In fact the whole api)aratus seems 

 like an everted pit. The termination of the cone varies in different 

 species. In some the end is blunt and even hollowed out; in others 

 there is a fine point at the a})ex ; in still others there are several 

 points. Figs. 41-45. The distribution of the cones is wide. They 

 occur in all the families of the Frenatje, excepting the Hesperiina 

 and Papilionina, and possibly the Fyromor[)hid:c. They are not 

 fi)und in the Jugataj. Notwithstanding their broad distribution, 

 there is usually only a single one on a segment, and in many cases 

 only on the segments of the distal portion of the clavola. 



* Physiologische uiid histologische Uiitersuchtunjieii iibcr dus Geruchsorfjander 

 Insekten, Gustav Hauser, Eiiangen. Zeit. fur wiss. Zool., vol. xxxiv, pp. 3G7-403 

 (1880). 



f Anteiiiialen Sinnesurgano. Zeit. fur wiss. Zool., vol. xlvi, i)p. G02-628. 



