51 



scured, their direct connection coidd be nnmistakably traced : 

 this appeai'ance is due simply to the invariable assumption by 

 these oro;ans of their natural attitude of rest. Havino- there- 

 fore followed these bifid stems to the maxillse, writers haA'^e 

 been content to leave them there, and have not traced them in 

 their more transparent parts, which were first clearly seen by 

 me in the specimen from Toronto. In specimens afterwards 

 mounted under pressure to separate the parts, the true charac- 

 ter of the inner lobe of the maxilla was proved beyond a doubt ; 

 for the jointed stem, still preserving its connections throughout, 

 became elbowed, and the apical joint was thrown so far to one 

 side as not to cross any part of the maxilla. 



The eyes of Atropos differ remarkably from those of other 

 Psocidae. As is well known, tlie Atropina generally are dis- 

 tinguished from the Psocina by the absence of ocelli ; and in 

 many forms throughout the family (especially in the males, as 

 Dr. Hagen informs me), the compound eyes appear to be only 

 an agglomeration of simple ocelli, each facet being strongly 

 convex, and the whole mass resembling a bunch of grapes. 

 Tliis is the case also in the specimen of Rhyopsocus referred to, 

 which is a female, and is believed by Dr. Hagen to belong to 

 the Atropina ; so that the characteristic of Atropos now to be 

 mentioned is not shared by all the other members of the Atro- 

 pina. The eyes of Atropos are extremely simple, and indicate 

 a low organization ; generally their form and composition are 

 extremely difficult to make out because of the amount of pig- 

 ment in the field where they are situated ; but in the specimen 

 from Toronto the eyes are unusu'dly distinct and uninjured, so 

 that their structure is perfectly clear ; they consist merely of a 

 row of three simple, equal, contiguous ocelli, on either side, 

 placed in a straight, oblique line next to the outer margin of 

 the under surface of the head just behind the middle, the outer 

 one upon the margin itself; the line is directed toward the base 

 of the mandibles, and the whole row is as long as the second 

 antennal joint. This is the simplest form of eye which is 

 known to me in a perfect insect ; indeed it would be difficult to 

 imagine anything much simpler. Samuel H. Scudder. 



