G. C. CRAMPTON 217 



standpoint of comparative morphology. !Metcalf interprets the 

 plates labeled c, which are situated on either side of the anus in 

 the syrphid shown in figures 23 and 22, as the cerci. I am more 

 inclined to regard these structures as the representatives of the 

 basal plates pp or paraprocts (parapodial plates, or protopodites), 

 which are situated on cither side of the anus and bear the cerci 

 la])eled c in the female dipteron shown in figure 21. Such para- 

 podial plates bearing the true cerci are also present in the mecop- 

 teron shown in figure 18, and in these insects the plates in 

 question are broad flattened plates, rather than the typical 

 cylindrical structures forming the cerci c of the dipteron shown 

 in figure 35, for example (or the cerci labeled c in the mecopteron 

 shown in figure 17). I have provisionally adopted the inter- 

 pretation of the plates labeled c in figures 9, 22, 23, etc., as the 

 cerci, however, since I cannot prove that they are the parapodial 

 plates (paraprocts) rather than the cerci, and Metcalf and 

 Berlese may be right in calling them cerci, though I feel that this 

 matter should be investigated from the embryological standpoint 

 ])efore it is regarded as definitely settled. 



As was mentioned above, the abdominal segments which bear 

 the anus are called the proctiger {pg of figures 33, 35, 38, etc.). 

 The ninth abdominal segment of the male, being the genital 

 segment par excellence, might be referred to as the gonomere 

 (the term andromere has also been proposed for it) . Its tergite 

 is here referred to as the epandrium, and its sternite as the hy- 

 pandrium. Its pleurite (also called the gonopleurite) may be 

 I'eferred to as the parandrium. These terms are much less 

 cumbersome than such designations as the "ninth abdominal 

 tergite of the male" (epandrium), the "ninth a]:)dominal sternite 

 of the male" (hypandrium) etc., and are proposed merely for 

 the sake of convenience and brevity. Since the terms ovipositor, 

 terebra, etc., are already in use for the external genital apparatus 

 of the female, the term genitalia may readily be restricted to 

 the accessory genital apparatus of the male, and is, in fact, so 

 used by a great number of investigators in the different orders 

 of insects. It would be preferable to apply the term "genitalia" 

 to the claspers and adeagus alone, but there is no objection to 

 including the accessory claspers (surgonopods) formed ])y the 



TRANS. AM. EXT. SOC, XLVUI. 



