NOTES ON THE GENITAL ARMATURE. b 



ment of unrecognised names and descriptive phrases for the various 

 organs. It is quite impossible for even those who have had consider- 

 able apprenticeship in the study of the genitalia to recognise what 

 organs are thus referred to. The want of uniformity in our termin- 

 ology is at once unnecessary and the cause of hopeless confusion, not 

 only to the student but also to the advanced worker. 



In this article before me I find that the names employed are for the 

 most part not generally accepted, or they are recognised names used to 

 denote quite other parts than they commonly signify, indeed one can 

 only hazard a very uncertain guess as to the organs to which they 

 refer. I select the following for comment. The Cla>tpfi fairly obviously 

 denote the valvse. The Te(/i(nien apparently denotes only the dorsal part 

 of the whole organ to which the name rightly belongs, but it also 

 appears to include the uncus, which in the article is only obscurely 

 alluded to. The Girdle one must conclude is used for the remainder 

 (by far the larger part) of the tegumen. When, however, we come not 

 only to an upper and lower girdle, but also to an inner and outer one, 

 I confess I have to give it up. The Falces can only stand for the 

 gnathos when the two arms of this organ are widely separated. The 

 Dorsum and Dorsal Bridi/e one judged to be the uncus. The Cnrtainis 

 a puzzle, but may denote the socii, whilst the Lateral Cheeks is a 

 descriptive expression that does not seem to help much. The Fidcrum 

 evidently represents the sacculi when projecting ventrally and fused 

 together, that is to say the furca. In addition to the use of such un- 

 recognised names, I find forwards and backwards, front and rear, 

 employed with the opposite of their usual significance, forwards here 

 denoting towards the tail of the insect, backwards towards the head ! 

 Sternite and tergite occur freely regardless of the fact that no settle- 

 ment has yet been attained as to what organs constitute these pieces, 

 whilst, perhaps wisely, the question as to which segment of the body 

 they belong is ignored. The expression, " the end segment of the 

 abdomen proper," leaves me wondering. 



Now with such a terminology it is not a matter of surprise that the 

 student is left baffled and in despair. What can he be expected to 

 make of this on page 316 ? " The girdle is erect, expanding suddenly 

 forwards below the tegumen, which is funnel shaped, deeply excavated 

 in front with the dorsum terminating in a blunt point. Whilst the 

 lower part is bifid, also terminating in blunt points, below these are the 

 falces, broad and strong, suddenly curved upwards near the tips with 

 one or two sharp teeth near the bend ; the apices of the lower part of 

 the tegumen are furnished plentifully wuth bristles, but the dorsum 

 very sparingly." Or of this again on page 320. " The general outline 

 . . . . to end of section." Or suppose he attempts to compare 

 the figure of Tirumala petiverana. No. 25, with the description on page 

 323, he can only conclude that the figure has been wrongly numbered. 



Now all this incomprehensible confusion is not only sad but un- 

 necessary. Dr. McDonnough, in the Canadian Kntninoloiiist for June, 

 1911, has given us a list of names which rightly belong to the different 

 parts under the law of priority. These names are now in common use 

 amongst workers, and I have given a list of them and others with full 

 explanations in -'The Genitalia of the Geometridse." If only writers 

 -would adopt accepted names the progress of our study would be 

 immensely facilitated, whilst much that is now incomprehensible to 



