ON SCENT ORGANS IN TRICHOPTERA. 459 
32. Scent Organs in Trichoptera. By Brucn F. Cummines, 
Baan Museum (Natural History) *. 
[Received April 3, 1914: Read May 19, 1914. | 
(Text-figures 1—8.) 
InpEx. 
Page 
wal GHAROLC KDVELOIEY So netobbosceroocadodoccs dad eRpaueHer Ree EERE REE eto co nes 459 
i. Historical . PI hte EO APE a te ath ead ans MR Re Cana Sn AO) 
i. Scent Crema f in incecte af eneansieeoe a WOO), 
ii. The Maxillary Palpi oo ho. TMleltes of s ericostoma 
personatwm ......... a Nasr Tem et TER Mona AA 
iv. The Scent Organs of Sop ioostome Pronsonaam eee AGS 
We laiberatire ees eens Se cen reat nae mck Stes ara Hl AS 
INTRODUCTION. 
Sericostoma personatum Spence is a tolerably common caddis- 
fly in Great Britain, and immediately attracts attention on account 
of the enormous development of the palpi of the first pair of 
maxille in line male. Unlike the maxillary pee of the female, 
which are 5-jointed and quite normal (text-fig. 1), the maxillary 
palpi of the male consist of but a single segment very much 
enlarged and shaped like a half-moon. These two palpi are 
placed together and held vertically so as to mask the front of the 
head (text-fig. 2, p. 463). 
Text-figure 1. 
Sericostoma personatum. 
Palpus of the first maxilla, 2. » 17. 
Despite their bizarre shape, these palpi have not obtained, 
so far as I am aware, that amount of enquiry into their 
nature and function which they deserve, and a résumé of their 
uneventful entomological history therefore will not detain us 
long. 
1, HisToricat. 
Kirby & Spence (1) regarded them as the genz or cheeks of 
the skull. Pictet (2), as McLachlan gravely points out, ‘ scarcely 
* Communicated by the SecRETARY, and published by permission of the Trustees 
of the British Museum. 
