ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 949 



system. Schobl's observations in regard to the changes in the females 

 after impregnation are confirmed. After the moulting the female 

 aperture is lost, and a brood-chamber developes. After young have been . 

 borne twice, the female moults and regains its apertures. 



Sexual Dimorphism in AmpMpoda.* — Prof. T. Barrels finds that 

 Mcera integrimana Hiller is the female of M. scissimana Costa, and that 

 M. Donatoi of Hiller is, similarly, not a good species, but the female of 

 M. grossimana Montagu. 



Development of Gammarns.l — Dr. Sophie Pereyaslawzewa com- 

 municates the first of a series of researches on the development of 

 Amphipods. The present memoir deals with Gammarus poecilurus Ethk. 



The living egg is first described in its initial and subsequent stages. 

 The author then briefly discusses the modifications exhibited previous to 

 segmentation. The segmentation itself and the establishment of the 

 layers are described. The derivation of the organs of the three layers 

 is followed in detail. Amoeboid movements were observed in the 

 embryonic cells, especially in those of the endoderm, and this not only 

 in Gammarus, but also in Caprella and Orchestia. The author reserves 

 general deductions until a larger number of forms have been investigated 

 by herself and her students. An appreciation of the results will then 

 be more readily made. 



European Daphnidse.f — Dr- E- Eylmann gives a valuable systematic 

 account of European Daphnidas. After giving a diagnosis of the family, 

 he distinguishes the five genera — Daphiia, Simocephalus, Scapholeheris, 

 Ceriodaphiia, and Moina. The (forty-seven) species are then diagnosed 

 in detail. JDaplmia curvirostris is noted as a new species. Tables for 

 specific identification, and one showing the distribution, increase the 

 value of this systematic monograph. 



Orchestia.§ — M. E. Chevreux has a note on the presence of Orchestia 

 Chevreuxi at Teneriffe, and a description of the male of this species. 

 With regard to the locomotor activity of this genus, he observed that, 

 in 0. littorea, the posterior part of the abdomen was always folded under 

 the body when the creature was moving on a horizontal plane, and that 

 the last five pairs of thoracic limbs were alone used. It was evident 

 that the longer they were the more easily could the creature move, so 

 that we may ascribe the difficulty of capturing 0. Chevreuxi to the great 

 length of its appendages. In an earlier essay || the author has some 

 remarks on the adaptation of Amphipods to a terrestrial mode of life. 



Amcebocytes of Crustacea.Tf — Dr. G. Cattaneo has a preliminary 

 notice of the amcebocytes of Crustacea, in which he discusses the struc- 

 ture and spontaneous modifications of the amoeboid cells of Carcinus, 

 their histological phenomena, and their variations in different surround- 

 ings and under the influence of various reagents. Prof. F. Leydig ** 

 calls attention to his description of similar bodies in his ' Natur- 

 geschichte der Daphniden,' published in 1860. There, too, are to be 

 found some observations on the corpuscles found in the blood and other 

 tissues of sick caterpillars. 



* Bull. Soc. Zool. France, xiii. pp. 57-9. 



t Bull. Soc. Nat. Moscou, 1888, pp. 183-219 (4 pis.). 



i Ber. Nat. Gesell. Freiburg, ii. (1887) pp. 61-li8 (5 pis.). 



§ Bull. Soc. Zool. France, xiii. (1888) pp. 92-6. || Tom. cit., pp. 59-66. 



% Zool. Anzeig., xi. (1888) pp. 452-5. ** Tom. cit., pp. 515-6. 



