GIO 



PSYCHE. 



[November — December 1SS3. 



species known to me, they commence 

 in a single row of minute denta- 

 tions on the fourth segment. The prin- 

 cipal features of this armature are the 

 following : — It is always the stronger in 

 the male sex — conspicuously so in C. 

 robiniae, but less so in C. centcr- 

 ensis : the teeth increase in size from 

 the fifth to the tenth segment : the 

 anterior row is ahvays the stronger in 

 each sex ; upon the llfth and sixth seg- 

 ments, it does not, in its lateral exten- 

 sion, reach below the stigma,^ while 

 upon the following segments it passes in 

 front of the stigma and quite a distance 

 beneath it : the posterior row is discon- 

 tinued before reaching the line of the 

 stigmata : the teetii show irregularity in 

 fonu and size, particularly those of the 

 posterior row. 



The sexual distinction above referred 

 to, presented in this armature, is this : in 

 the male pupae two rows of teeth occiu' 

 on segments five to ten inclusive; in the 

 female, two rows on five to nine inclu- 

 sive. In other words, the male pupa 

 shows TWO 7-01VS of teeth on segment 

 ten, where the female shows but O'su. 

 In each sex, the eleventh and twelfth have 

 but a single row. Disregarding, as I 

 think we should in onlinary usage, the 

 subdivision of what is usuallv known as 

 tlie terminal segment, into demi-seg- 

 ments, or a segment and a subsegment, 

 and that still farther refinement which 

 would make of the extreme portion 

 an additional segment with full numeri- 

 cal designation, then it will serve to 

 prevent misapprehension of the parti- 



8 In C. ceiiterensis it reaches below the stigma on the 

 sixth. 



cular section showing the sexual teatme, 

 if we indicate it as the antepenultimate 

 sen-men t. It would be the eleventii, if 

 we commence enimieration, as some of 

 om- entomologists do, with the head, but 

 the tenth, if, as seems to me more pro- 

 per, we begin with the first thoracic 

 ring. 



Beside the cossinae, this same sexual 

 feature occurs in the aegeriidae. I am 

 not able to say if it extends througiiout 

 the entire familv. At the time of this 

 present writing, I have at mv command 

 onlv the pupae of Acger/'a exitiosa and 

 A. tipuliformis. and it exists in each. 

 It probablv occurs in the pupae of 

 Zeuzera (one North American species 

 described), in which the two rows of 

 teeth are found on several of the seg- 

 ments, and perhajis also in Hcpiahis, 

 the pupae of which (unknown to me) 

 are characterized as vcrv similar to 

 those of Cossus. 



Another interesting fact connected 

 w ith the armatm-e of Cossus is that the 

 form, size, and position of the teeth vary 

 to so great an extent in the ditlerent 

 species, and show such distinctive char- 

 acters, as to afford excellent specific 

 features.' I would not hesitate to pro- 

 nounce upon specific identity, upon an 

 examination and comparison of the 

 pupal armature alone. 



" For comparison with other species of the cossinae 

 it may be stited that an example of C. rtnterensis rf 

 lias thirty. ei^ht teeth \n the anterior row of the tenth 

 segment, and twenty teeth in the posterior row — the 

 latter, in their entire range, occupying a transverse 

 sjiace etinal to that of niTic teeth of tlie anterior row. 

 Tlie teeth are black, shininy:, irregular in size, and are 

 slightly bent upward over their base; their length and 

 the distance between their tips exceeds their basal 

 width 



