552 SUMMARY OF CURRENT RESEARCHES RELATING TO 



suspension when the ventral ganglia are separated from the oesophageal 

 oollar, it does not take place. The act may therefore be voluntary, but 

 there is also a reflex autotomy. 



New British Cladocera.* — D. J. Scourfield records from the neigh- 

 bourhood of Scarborough Alona tveUnerl Keilhack, and Phuroxus 

 deiiticulatus Birge from Exminster, Devonshire. This latter form is 

 typically American, and has not previously been recorded from this side 

 of the Atlantic. 



DifFerentiation in Regenerating Antennule of Asellus.f — C. 

 Zeleny finds that in Asellus the differentiation of the segments in the 

 proliferating cell-mass appears first at the base. This is followed soon 

 by the appearance of segments at the tip ; lastly they appear in the 

 middle. The region of new growth is then located in one of the middle 

 segments, differentiation proceeding on both sides of this. Growing 

 antennules in young animals show the same method of development. 



Behaviour of Larvae of Cambarus.| — E. A. Andrews gives an 

 account of the behaviour of larval Gamharus clarkii and G. diogenes in 

 association with the parent, and describes the structural relations of the 

 attached larvse. These larvae associate with the parent in the first and 

 second stages and in part of the third ; this sort of family life is aided 

 both by special recurved tips on the chelae and by a peculiar telson 

 thread, by means of which the larva is suspended from the mother until 

 able to use its claws. Subsequently it holds on by these to the egg- 

 stalk or to the maternal pleopods. 



New Cypridina from Melbourne.§ — F. Chapman describes Gypridina 

 thielei sp. n. from Hobson's Bay, Melbourne, where it appears to be 

 abundant. This form is remarkably phosphorescent ; " inclosed in the 

 live box, they were seen to emit a strong steel-blue light for about 10 

 minutes, and when the luminosity became faint it could be speedily 

 increased by the application of slight pressure." The females of this 

 species are probably natatory, though this appears to be exceptional in 

 this genus. 



Fresh-water Isopod from Calcutta.! — T. R. R. Stebbing describes 

 Tackma spongillicola sp. n., found by Nelson Annandale in the 

 canals of a sponge in a fresh-water pond at Calcutta. The hitherto 

 known species of Tachma are T. crassipes Schiodte and Meinert from 

 coral-reefs at Singapore, and T. incerta H. J. Hansen, of unknown 

 locality. The author is inclined to believe that T. incerta is not 

 distinct from T. crassipes, and that T. spongillicola is a very near 

 relation of the same species, distinguished chiefly by the terminal joint 

 of the maxillipeds, but apparently also by having the limbs somewhat 

 less spiny and the pleon shorter in comparison with the perason. At 

 some future opportunity it would be interesting to test by experiment 

 whether the fresh-water form could support life in sea-water. 



* Journ. Quekett Micr. Club, April 1907, pp. 71-6 (1 pi.). 



t Proc. Indiana Acad. Sci., 1905, p. 159. 



X Amer.Nat., xli. (1907) pp. 253-74 (2 pis.). 



§ Proc. Roy. Soc. Victoria, n.s., xix. (1906) pt. 2, pp. 28-32 (1 pi.). 



II Journ. Linn. Soc. (Zool.) xxx. (1907) pp. 39-42 (1 pi.). 



