Packard.] 



270 



[Sept. 



palpi are atrophied. But while the second maxillae of the Termitidse and 

 Perlida3 are well developed, the degraded condition of those of the Pso- 

 cidaj affords a passage, though not a direct one to be sure (the labial palpi 

 in Psocus and Atropos being simply one-jointed and there being no para- 

 glosste), to the Mallophaga. We copy, however, the accompanying sketches 

 from Mr. Burgess' paper, so that the reader may compare the mouth-parts 

 of the Psocidse with those of the Mallophaga. 



Figs. 10, 11.— Psocus. 10, side view of the head ; d, clypeus ; Ihr, labrum ; in, mandible ; 

 mx, maxilla ; /, fork ; c, cardo; 11, m, mentum ; Ip, labial palpus ; lig, ligula. 

 Fig. 12.— Atropos, labium. Ip, palpus ; mx, maxilla.— After Burgess. 



In the general form of the body, especially the shape of the thoracic 

 segments as compared with the abdomen, the wingless Atropos shows a 

 decided resemblance to the bird-lice. In the first place, 

 the head is in both groups very large, while the thorax 

 shows a greater or less tendency to be merged into, or be 

 less differentiated from, the abdomen. The latter region 

 has ten segments both in Atropos and the Mallophaga. 

 In Atropos there are three, in the Mallophaga two tarsal 

 joints. 



The eyes of Atropos are much reduced, there being 

 from three* to seven simple ocelli on each side ; in the 

 Mallophaga the greatest number is two on each side. 



After the foregoing portion of this paper was written, 

 I read Nitzsch's paper (Germar's " Magazin der Ento- 

 mologie," Bd. iv, 276-290, 1821) on the internal anat- 

 omy of Atropos pulsaiorius, and found unexpected con- 



FiG. 13. —Atropos finnation of the view we have taken as to the relation- 

 pulsaionus. Author 



del. ship of the Mallophaga to the Psocidie. His observa- 



tions, he says, were the result of researches carried on about the year 

 1814, at the time he was occupied with the study of the Mallophaga. 

 "I undertook," he says, "the dissection of 1 ho Psocus, because this in- 



* Scudder found but tliree simple-eyes on a side in an Atropos he examined, 

 ii, 51. 



Psyche. 



