ON THE CONJUGATION OF PERIDEA TREPIDA. 53 



On the conjugation of Peridea trepida (in'th plate). 



By T. A. CHAPMAN, M.D. 



Students of the male ancillar^^ appendages of lepidoptera are 

 familiar with certain small spines [roniiiti (misprint for cornidi ?) 

 of Pierce] , very varied in form, size, arrangement and number, that 

 arm the eversible membrane (resica of Pierce) of the aedoeagus. It is 

 also very general!}' known that in a few cases these corimli in conju- 

 gation, break away from the vesical membrane, and are left behind 

 in the bursa of the female. I have obtained specimens and photo- 

 graphs illustrating this fact in several species, and have hopes of 

 enlarging the series. 



However, am lonr/a, and I may not attain to being able to set forth 

 the subject in any definite order ; indeed, the cases so far known to 

 me are distributed erratically in various totally unrelated families, and 

 a due co-ordination of these must mean a long and wide research. It 

 seems, therefore, not undesirable to set forth one of the most remark- 

 able of these cases, with a view to interesting a larger number of 

 observers in the subject. 



I owe to Mr. Burrows the knowledge that the fedceagus of F. 

 trepida contained a collection of star-like bodies. An examination 

 of a number of specimens showed that these very curious bodies 

 were swimming quite free in a dilatation of the eversible tube in 

 the fedceagus of S" specimens of i'. trepida that had never paired, 

 but that they were absent from those individuals that had paired. 

 Further, that in females that had paired, the bursa contained a swarm 

 of these bodies, which were quite absent in the case of virgin females. 



As most specimens of P. trepida in collections are bred, it was less 

 easy to obtain specimens that had paired than in the case of many 

 other insects. 



There can be no doubt that these little stellate bodies of dark 

 chitin, wdth their five to eight raj^s, are identical in all respects with 

 Pierce's cnrnidi, are in fact cornidi, yet they are unattached. It would 

 probably be safe to assume that, at a date earlier than the complete 

 maturity of the jnale moth, these cornidi have an attachment as in 

 other cases, but certainty can only be attained by examining moths in 

 different stages of development before they emerge from the pupa. 



Probably other species of Peridea are similarly provided ; these I 



have had no opportunity of examining, but I have examined a large 



number of other Notodonts without meeting, not merely with any 



similar arrangement, but with anything that could be supposed to be 



. any stage in the evolution of this remarkable arrangement. 



The photographs show a portion of the cedoeagus of P. trepida g , 

 crowded with these caltrop-like engines x 45 (pi. iii., fig. 2). The 

 other shows the bursa of the $ , containing a large number of the 

 same structures ; this is only magnified 20 diameters (pi. iii., fig. 1). 

 I do not figure these same organs devoid of these irritating particles, 

 for the simple reason that they practically show nothing ; yet it 

 is perhaps necessary to say that I have found several specimens of 

 these also. 



These remarkable structures occurring nowhere else amongst the 

 species with which trepida has been associated by Kirby, Meyrick, 

 Hampson, Staudinger, etc. {i.e., with dnnitedariua, dictaea and other 

 March 15th, 1910. 



