358 DR. F. B. WHITE ON THE MALE GENITAL 



number — one superior, and two lateral. The lateral are the equivalents of the appendices 

 inferiores in the Trichoptera, and in this paper will be termed the ''• harp agones" 

 (harpago -onis, a grappling-hook). The upper appendage may be the equivalent of the 

 pair known as the appendices superiores in Trichoptera ; but though sometimes deeply 

 bifurcate, it yet consists of only one piece, which I will call the " tegumen " {tegumen, 

 a cover). 



On dissecting the parts more deeply, it will be seen that the tegumen, though most 

 largely developed in the dorsal arc (or tergite) of the segment, is continued as a chitinous 

 ring more or less round the ventral arc (or sternite) (PL LV. figs. 4 a, 10 c, 11 c, 12 c, and 

 13 c). The harpagones arise either from within the ventral portion of the tegumen, or 

 are superimposed on that part (PL LV. figs. 4 d, 10 d, 11 d, 12 d, 13 d). 



I will not at present say any thing further about the deeper anatomy, or concerning 

 the development of these structures, which probably represent the eighth abdominal 

 segment. 



More or less immediately below the tegumen is situated the anal opening of the 

 alimentary canal (PL LV. figs. 10 a, 11 a, and 12 a) ; and below that, again, is the intro- 

 mittent organ with its sheaths (PL LV. figs. 4 c, 10 b, 11 b, and 12 b). In the latter good 

 characters will probably be found to exist ; but as very frequently a good view thereof 

 cannot be obtained in a dry specimen, and as the soft parts are more or less altered by 

 desiccation, further allusion thereto will not be made in this paper. Part of the structure 

 is incidentaUy figured in PL LVI. fig. 26 a and PL LVII. fig. 13 d. 



In the female Lepidopteron the armature is much less developed, and the parts suffer 

 so much in desiccation that an examination of fresh specimens is absolutely necessary. 

 In some cases, however, the structure of the apical and penultimate abdominal segments 

 present interesting structural characters. 



Before proceeding to give some details of each part of the armature, I may state that 

 I have examined many species in addition to those mentioned and figured. 



The drawings have been made by the camera lucida, except the diagrams PL LV. 

 figs. 10, 11, 12, & 13. 



They have been made from dry specimens, which are better suited for the purpose than 

 fresh ones. In the latter the necessary operation of removing the hairs and scales is 

 apt to result in causing the parts to assume unnatural positions, while the parts are 

 sufficiently hard not to be altered in form by desiccation. 



In giving side views I have only figured the parts next the eye, though frequently the 

 corresponding parts on the opposite side are more or less visible ; nor have I figured 

 the sheaths or other parts of the intromittent organ that were visible in some cases. 



The drawings (and descriptions) only attempt to give an idea of what is visible without 

 an alteration of the position of the object under the microscope. The same part viewed 

 in a very slightly different position will often present quite a different form ; so that to 

 arrive at a correct idea of the structure the part itself must be examined. As much care 

 as possible, however, has been taken to place in identical position the parts figured in the 

 different species, in order that a just comparison may be made. 



