^''ol. XXviii] ENTOMOLOGICAL NEWS. 399 



ment to the head is much more ''Lepismid-hke" in the Plecop- 

 teron (Fig. 4) than in the Blattids (Fig. 2). In the same way the 

 location of the "compound" eyes, and the position of the anten- 

 nae are quite similar in the Lepismids and Plecopteron ; but 

 both differ strikingly from the Blattids in these respects. The 

 clypeus and labrum also, are more alike in Lepismids and the 

 Plecopteron, than these structures are in the Lepismids and 

 Blattids, and the mandible of the Plecopteron is nearer the 

 Lepismid type than the Blattid mandible is. In other words, 

 the evidence to be gained from a comparative study of the ex- 

 ternal morphology of the head, would point to a close relation- 

 ship between the Lepismids and the Plecoptera, and a much 

 more distant relationship between the Blattids and Lepismids. 



In taking up a consideration of the neck and thoracic regions 

 in the Lepismids one finds (as might be expected) that the 

 Lepismids have retained a condition resembling that found in 

 the lower Apterygotan forms (such as Japyx, Eosentomon, 

 etc.) rather than such a condition as occurs in the Pterygotan 

 insects. The thoracic sclerites of Japyx, Eosentomon, etc., have 

 been homologized in a paper dealing with the nature of the neck 

 region of insects in general (which will shortly appear,* 

 in the "Annals of the Entomological Society of Amercia"), so 

 that it is unnecessary to describe them here, since one may 

 simply compare the accompanying figure of Lepismo (Fig. i) 

 with those of Japyx, Eosentomon, etc., in the aforementioned 

 article. I would call attention, however, to the anterior trans- 

 verse pronotal sclerite designated as "Pt" in Fig. i. This 

 sclerite is clearly the homologue of the transverse pronotal 

 sclerite labeled "Pt" in Figs. 9 and 7 ; and it is in the tergal 

 region that the Lepismids apparently approach the condition 

 found in certain lower Pterygota, more closely than in any other 

 thoracic structures. 



The trochantin-like region "abc" (termed the "eutrochantin" 

 in the paper referred to above) of the Lepismids (Fig. i) is 

 also somewhat similar to that found in Figs. 6 and 7, since it 



* Subsequently published in Vol. X, page 187, of the "Annals" for 

 1917. 



