

PSYCHE. 



ORGAN OF THE CAMBRIDGE ENTOMOLOGICAL CLUB 



EDITED BY GEORGE DIMMOCK AND B. PICKMAN JIANN. 



Vol. II.] Cambridge, Mass., July-Aug., 1877. [Nos. 39-40. 

 On the Structure of the Head of Atropos. 



The inner lobe of the maxillae of the Psocidae has always 

 been described, so far as I can learn, as a simple, unjointed, 

 horny stem. Thus Burmeister ^ says it is a slender horny 

 piece like a fish bone, which lies deeply imbedded in the base 

 of the jaw, is sharply separated from the galea, and, when the 

 mouth is closed, often projects near the labium. Westwood '^ 

 describes the same part as a long, slender, curved, horny pro- 

 cess, arising from the base, and longer than tlie maxillae, and 

 figures the same (fig. 59.4, p. 18) as a nearly straight and sim- 

 ple unjointed rod, with a bifid tip. Latreille also gives a similar 

 account of its structure. The special monographers of the 

 family seem never to have given any general outline of the 

 structure common to the group, but have limited themselves 

 to those features wherein its members differ from one another ; 

 I cannot find any allusion by them to the special composition of 

 the maxillee. 



A specimen before me, found in a mass of clay lately taken 

 from an interglacial deposit near Toronto in Canada, but which, 

 was probably accidentally introduced after the removal of the 

 deposit, is remarkably free from discoloration and the grayish 

 particles usually accompanying mounted specimens of Atropos. 

 This specimen shows a structure of the inner lobe different 

 from that hitherto described, and repeated examinations ot 

 fresh specimens have left no doubt that the structure has been 



1 Handb. d. Entom., ii, 722. 



- Modem Class. Ins., ii, 17. It may be remarked that Westwood correctly describes 

 the outer maxillary palpus as four jointed, although he figures it with six joints. 



