66 - THE REPORT OF THE No. 33 



Spines. The chitinous dentations or spines are arranged transversely on 

 the segments, pointing away from the head. The arrangement is slightly 

 different in each sex. 



Segment 1, which is reduced in size, shows only one row of very fine spines. 

 On segments 2 to 9 are the larger, rounded, somewhat spear-shaped teeth, 

 darkly tinted on the outer margin, each tooth being clearly visible to the naked 

 eye. There is also an additional row of much smaller, finer, spine-like processes 

 arranged transversely caudad to the larger and which can be seen only with the 

 aid of a hand lens. These appear on segments 2 to 6 in the female and on 

 segments 2 to 7 in the male. Segment 10 has several coarse spines, irregular 

 in size, arranged somewhat semi-circularly, the largest being situated ventrally. 



In both sexes the large, coarse teeth are fairly regular in outline. The 

 largest of these in each row are situated mid-dorsally and taper off gradually 

 as they run out laterally, passing down some distance beneath the spiracular 

 line and in front of the spiracle on all segments except the first three. In segment 

 1 the entire row is absent; in 2 they terminate just above the spiracle; and in 

 3 they run to the top of the spiracle. 



Genitalia. The anterior' genital opening of the female is situated on the 

 posterior border of the 8th segment; the caudal opening appears on a heavily 

 chitinized area of the 9th segment (see figure). 



The genital opening of the male is associated with the 9th segment (see 

 figure). 



Anal Opening. The anal opening situated near the caudal margin of the 

 10th segment is slit-like and surrounded by prominent folds. 



Abdominal Seta. The abdominal setae, Fig. 5, are inconspicuous and 

 occupy positions slightly different from those of the larva. The following is 

 a tentative homology based on the nomenclature of the larval setae introduced 

 by S. B. Fracker in "The Classification of Lepidopterous Larvae" of Illinois 

 Biological Monographs, Vol. II, No. 1, July, 1915. 



a. very small, close to the cephalic border of the flanged plate, about half 

 way between the dorso-meson and the spiracle. 



/3 under the anterior row of spines nearer the dorso-meson than a 



p under the same row of spines close to and dorsad of the spiracle. 



k on the posterior border of the flanged plate directly cephalad of the 

 spiracle. 



V under the anterior row of spines close to and ventrad of the spiracle. 



p- on the posterior border of the median area, caudad of the spiracle (very 

 indistinct, and absent in many cases). 



■n- Group — usually bisetose, cephalad and slightly laterad of the proleg 

 scar. 



°" is between the prolegs scars. 



a, k and m- are represented by punctures only; elliptical in outline. 

 Certain depressions or scars, the nature of which could not be determined 

 occur dorsad of the spiracle and might easily be mistaken for setal 

 vestages. (See Fig. 5.) 



