ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 667 



placed in water up to about 1 • OOtf, and showed no ill effects. Some 

 became inured to 1*005, 1*0075, and 1*01; but higher solutions were 

 always fatal. Eggs were hatched in 1*01 and weaker solutions, and 

 developed normally and at the normal rate, but the larva? showed no 

 increased power of resistance. There is therefore a very definite barrier 

 to the assumption of marine life, and the barrier remains unchanged 

 during the life of the individual. 



Permian Odonata.* — E. H. Sellards discusses the Odonata found in 

 the Permian of Kansas, which is the most complete record of Permian 

 insect life as yet known. Over two thousand specimens have been ob- 

 tained, showing that the Permian insect fauna was very rich. In dis- 

 cussing the Odonata obtained for the first time from the Permian, the 

 author devotes his attention particularly to a new type which he calls 

 Tupus permianus. He shows that the main veins of the wings in Car- 

 boniferous and Permian dragon-flies present an arrangement in agree- 

 ment as regards major characters with that of both Mesozoic and modern 

 forms. 



Stridulation of G-ryllus campestris.+ — Alois Kreidl and Johann 

 Eegen have investigated with the help of the phonograph the number 

 of vibrations in the stridulation-note. They have estimated the number 

 of times per minute that the wing surfaces are rubbed against one 

 another, and have made a careful study of the details of the complex 

 instrument. 



Spermatogenesis in Locusta viridissima.} — H. Otte finds that all 

 the chromosomes change in the young spermatocytes into filaments, 

 which become longitudinally apposed to form bivalent double-filaments. 

 These are twice divided transversely. There is a single accessory 

 chromosome, the simple univalent-filament of which is divided once 

 transversely in the second maturation division. Thus in the two trans- 

 verse divisions there is no proper reduction (in Weismann's sense), since 

 no entire chromosomes are separated from one another. The two 

 chromosomes which conjugate to form a single bivalent chromatin 

 element are twice halved transversely, but they do not part company. 



Notes on Machilidae.§ — F. Silvestri describes a new genus Alloma- 

 chilis, allied to Machiloides, represented by A. frogatti sp. n. from New 

 South Wales. Five other new species are described, and the author 

 makes various notes on the family, and gives a diagnostic key to the 

 genus Machilis. 



Key to Families and Genera of Thysanura.|| — C. F. Jackson has 

 prepared a useful diagnostic key to this order of insects, based on Dalla 

 Torre's monograph. 



Injurious Insects of the State of New York.1[— E. P. Felt 

 discusses a number of injurious insects, e.g., the grape-root worm (Fidia 



* Amer. Journ. Sci., xxii. (1906) pp. 249-58 (8 figs.), 

 t SB. Akad. Wiss. Wien. cxiv. (1905) pp. 57-81 (1 pi.). 

 X Zool. Anzeig., xxx. (1906) pp. 529-35 (14 figs.). 

 § Redia, iii (1905) pp. 325-39 (13 figs.). 

 || Ohio Naturalist, vi. (1906) pp. 545-9 (7 figs.). 



•jf New Y/ork State Museum, Bulletin 104, Entomology 26, Albany, 1906, pp. 

 49-156 (10 pis.). 



