ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 461 



North American Isopods.* — Miss H. Kichardson gives a synopsis of 

 the Chelifera, Flabellifera, and Valvifera, followed by one of tne Asellota, 

 Oniscoidea, and Epicaridea. 



New Victorian Blind Amphipod. f — Mr. 0. A. Sayce describes 

 Niphargus pulchellus sp. n., a snow-white blind form from a fresh-water 

 pool in Thorpdale, Gippsland. It is well characterised, and differs from 

 N. montanus in the more slender body, narrower side-plates, the want of 

 eyes, the elongated last pereiopods, and the greatly extended unibranched 

 jointed terminal uropods. 



New Subterranean Isopod.* — MM. Adrien Dollfus and Armand 

 Yire note the discovery of what is apparently a new species of Caeco- 

 sphseroma, found in an underground stream near the village of Sauve. 

 The new form is described as C.fauclieri, and, like the four other known 

 species of Sphaeromedae from subterranean waters, is totally blind, 

 bears tactile bristles on antennae and legs, and has four olfactory lamellfe 

 on the upper antennae, the lamellae being longer and reaching a higher 

 degree of development than in any Isopod hitherto described. 



Sacculina on Pilumnopseus serratifrons.§ — Mr. D. G. Stead de- 

 scribes a species of Sacculina parasitic on the above-mentioned littoral 

 crab, which is very abundant in Port Jackson. The parasite affects 

 both sexes, and is occasionally as large as the body of its host. It is 

 very noticeable, however, that all the specimens infected were of small 

 size. Neither the pleons nor the abdominal appendages of either sex 

 are modified in any way ; but growth is retarded and reproduction is 

 stopped. The crabs do not seem to interfere with their parasites, but 

 in one instance, after repeatedly wounding the parasite, the author saw 

 the crab completely dislodge the Sacculina, which proves the possibility. 



Entomostraca and the Surface-film. || — Mr. D. J. Scourfield notes 

 that only a few species of Entomostraca are capable of utilising the 

 surface-film for support, and of these all belong to the genera Scapho- 

 leberis and Notodromas. In Scapholeberis mucronata the supporting 

 mechanism is as follows : — On the ventral margin of each valve there 

 is a series of setae. The animal habitually swims in the reversed 

 position, and these setae pierce the surface-film and produce capillary 

 depressions. The coloration of the animal seems adapted to this habit ; 

 for the characteristic dark tint of the ventral surface must render it in- 

 conspicuous when looked at from above against a muddy bottom. 



Organism and Environment.1T — Dr. Ernest Warren has conducted 

 a suggestive series of experiments on Daphnia magna, and its reaction 

 to changes in the environment. The special objects of the experiments 

 were to determine the effect of the addition of sodium chloride to the 

 water, and of a confined volume of water. The author finds that the 

 times of killing with varying strength of solution of sodium chloride 

 are, within certain limits, well represented by a rectangular hyperbola. 



* Amer. Nat., xxxiv. (1900) pp. 207-30, 295-309 (16 figs.). 



t Proc. R. Soc. Victoria, xii. (1900) pp. 152-9 (1 pi.). 



j Comptes Rendus, cxxx. (1900) pp. 1564-6. 



§ Proc. Lirm. Soc. N. S. Wales, xxiv. (1900) pp. 687-90. 



|| Journ. Quekett Micr. Club, vii. (1900) pp. 309-12 (1 fig.). 



i Quart. Journ. Micr. Sci., xliii. (1900) pp. 199-224 (4 figs.). 



Aug. 15th, 1900 2 I 



