THE CANADIAN ENTOMOLOGIST 111 



tera than it is like that of many other injects grouped with them in the order 

 Psocida. and the range of variation in the wing venation of members of this 

 order covers far greater differences of venation than that between the Psocid 

 group Archipsocinae and the Zoraptera. The genitalia of the Zoraptera, how- 

 ever, are quite different from the genitalia of the Psocids, the Zoraptera have 

 well developed cerci, which are absent in all Psocids of which I have any know- 

 ledge, the head is of a more primitive type (and the mouthparts also) in the 

 Zoraptera, as is also true of the thoracic sclerites of the sternal and pleural re- 

 gions, and many other features, which would preclude our placing the Zoraptera 

 in the same order with the Psocids, although the relationship between the two 

 groups is far closer than has hitherto been supposed to be the case. 



The fore wing of Archipsocu,^ brasitianits shown in Fig. 10, Plate III, is 

 strikingly similar to that of Zorotypns snydcri shown in Fig. 12. since in both 

 insects, the cubitus is two-branched ( i.e. it divides into "Cui" and "Cu^"), while 

 the median vein "M", is unbranched and bends upward toward "R^" very abrupt- 

 ly, forming a slight connection with the latter, before bending down again to- 

 ward the posterior margin of the wing. Vein "R^^" is very similar in both in- 

 sects, and a comparison of Fig. 12 with Fig. 10 would indicate that in Zorotypns 

 snyderi (Fig. 12) vein "R4+r," has become lost, while only the branch "R2+»" of 

 the two branches of "R j, '' present in Fig. 10, persists to form the terminal por- 

 tion of the vein labeled "R^ " in Fig. 12 i.e. the portion labeled "R^ + 3" in Fig 12). 

 The pterostigma "ps" is very similar in both insects, and the fore wings of Zor- 

 otypns snyderi and Archipsocus brasilianns exhibit so many tendencies in com- 

 mon in their modifications, that one cannot escape the conclusion that the two 

 msects are extremely closely related. 



In Archipsocus brasilianus (Fig. 10) as in Zorotypns snyderi (Fig. 12) 

 vein "M" of the fore wing is barely connected with "Rg"; bwt in Archipsocus re- 

 cens (Fig. 9) vein "M" of the fore wing has coalesced with vein "R^" for a 

 considerable distance to form "Rg+M", and the same is true of the fore wing of 

 Zorotypn,s, hubhardi shown in Fig. 11. We thus have the modificational tenden- 

 cies exhibited by the fore wing of Archip.s.ocus brasilianns repeated in the Zor- 

 apteron Zorotypns snydcri, while the modificational tendencies exhibited by the 

 fore wing of Archipsocus rccens are repeated in the Zorapteron Zorotypns hnb- 

 bardi; and anyone who will compare the fore wings in the two groups of insects 

 must be impressed with the remarkable similarity between the two types ol 

 wings. 



The resemblance between the hind wings of the Zoraptera and Psocitls 

 is no less remarkable than the resemblances exhibited by the fore wings in the 

 two groups of insects. Thus, in the hind wing of Zorotypns snyderi shown in 

 Fig. 3 (which is almost exactly like that of Zorotypns hnbbardi), vein "R2-1-3" is 

 almost an exact counterpart of vein "Rj+ 3" in Fig. 5 of the hind wing of Archip- 

 socus recens, as is also true of vein "M^" in both insects. Vein "Rg" has united 

 with "M" and with "M+ Cu" for a greater distance in the insect shown in Fig. 3 

 than in the insect shown in Fig. 5, and the small cell just below the label "Rg" 

 in Fig. 5, has become obliterated in Fig. 3; but the cubitus "Cu^" is much the 

 .«;ame in the two insects.although the anal lobe "al" of Fig. 5, is not represented 



