576 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Stigmata of Dragon-fly Larvae.* — Alvar Neander has examined a 

 Dumbei of JSschnid and Libellulid larva' and finds that they have an 

 open tracheal system. During the larval life the stigmata undergo 

 further development, and the first pair is most differentiated. 



Prolapsus recti in Dragon-fly.t — Kan Oguma noted on a living 

 dragon-fly, Somatochlora viridisenea Uhler, a white body hanging out at 

 the anal end. A section showed that this was the hind intestine of the 

 insect, torn off from the rest of the alimentary canal at the posterior 

 end of the pylorus and completely evaginated through the anus. The 

 sections proved that the gut had been turned inside out. It is suggested 

 that the prolapsus may have something to do with the physiological 

 state which leads to the ecdysis of the rectal tracheal gills during the 

 metamorphosis. 



Anoplura and Mallophaga from Zululand.J — Vernon L. Kellogg 

 and G. F. Ferris report on a collection of Anoplura from Zululand 

 rodents and of Mallophaga from Theristicus hagedash, the Hadada Ibis. 

 The Mallophaga include Lsemobothrium setigerum Piaget, var. africanwn 

 var. nov., L. setigerum Piaget, var. cicbensis var. now The Anoplura 

 include PolypJax otomydis Cummings, Holopleura intermedia sp. n., 

 H. enormis sp. n., a striking form, marked by the enormously prolonged, 

 fingerdike prolongations of the pleura. 



New British MachilidseJ — Anna J. Reilly describes Petrobius 

 vectensis sp. n., from the Isle of Wight, and Petromachilis longicornis 

 g. et sp. n., from Cumberland and Caldey Island, off South Wales. The 

 new genus Petromachilis is intermediate between MachiJis and Petroiius, 

 agreeing with Machilis in having paired processes on both the eighth 

 and ninth abdominal segments in the male, and with Petrobius in having 

 no scales on the antenna? except on the two basal segments, while it is 

 intermediate between the two genera with regard to the mandible. It 

 may be distinguished from the other British genus of Machilidae, Prse- 

 machilis Grassi, by the presence of two pairs of exsertile vesicles on the 

 second to the fifth abdominal segments inclusive, Prsemachilis having 

 not more than one pair of vesicles on any abdominal segment. 



5. Arachnida. 



Blood-Sucking Gamasid Mite on Couper's Snake. ||— Stanley Hirst 

 describes Ichorongssus serpentium sp. n. (?), five females of which were 

 found on a Couper's Snake in the London Zoological Gardens. It is 

 quite probable that the species may be the same as that to which the 

 name Dermanyssus natricis was given in 1844 by Gervais, Ophionyssus 

 natricis in 1884 by Megnin. In having two dorsal shields and also 

 minute intermediate platelets, the adult females present a strong resem- 

 blance to the protpnymph stage of certain other species of IcJioronyssus, 

 such as /. bacoti Hirst. 



* Arkiv Zool., viii. (1913) No. 14, pp. 1-5 (2 figs.), 

 t Anat. Zool. Japon, ix. (1915) pp. 63-6 (3 figs.). 

 I Ann. Durban Mus., i. (1915) pp. 147-58 (2 pis.). 

 § Ann. Nat. Hist., xvi. (1915) pp. 10-15 (5 pis.). 

 || Proc. Zool. Soc, 1915, pp. 383-6 (2 figs.). 



