196 SUMMARY OF CURREiNT RESEARCHES RELATING TO 



in so many males and so many females are concentrated on a single 

 offspring which is, so to speak, pulled in two directions. 



Note on Daphnia atkinsoni.* — E. de la Vaulx discusses this 

 species first descril)ed by Baird in 1871) from Jerusalem, and afterwards 

 reported from Austria, Sweden, Russia, Spain, Greenland, and England. 

 The author records its occurrence in France. Gurney has noted its 

 abrupt appearance and disappearance in a marsh in Norfolk. The 

 antennule of the female is very characteristic. It is sub-cylindrical and 

 of large size : it bears terminally a number of relatively short sensitive 

 rodlets ; it lias at its base externally a sensitive transparent seta rising 

 from a clear disk. In the moult the carapace of the valves, instead of 

 separating definitely from the cephalic part of the cuticle, is prolonged 

 upwards in a heart-shaped portion. This piece is seen at the top of the 

 ephippium and gives it a characteristic appearance. The resting eggs 

 are disposed obliquely in unequal sub-triangular compartments. 



Cirripedia of Chilka Lake.f — Nelson Annandale reports that two 

 species, Dichelmpis cor Aurivillius and Balamis amphitrite Darwin, occur 

 abundantly in the outer channel of the lake, where they probably breed. 

 Larvae of B. amphitrite almost certainly enter annually from the sea. 

 In the main area of the lake a few specimens of B. amphitrite. were 

 noticed on rocks and lioats. This species grows very rapidly and has 

 great vitality. They often attach themselves to prawn-traps which lie 

 exposed on the shore during the heat of the day. The other form, 

 Dichelaspis cor, habitually occurs in the gill-chamber of a crab, Scylla 

 serrata. 



Annulata. 



Oligochaeta of Chilka Lake.+ — J. Stephenson notes that the Oligo- 

 chffita of l)rackish water are few, and do not form an independent 

 ethological group. They seem to be forms belonging to the fresh-water 

 or littoral groups, which possess the power of resisting a certain 

 amount of admixture of salt or fresh water respectively. He describes 

 from Chilka Lake Enchytreeiis l/arkiidmsis sp. n., Pontodrilns her- 

 mudensis Bedd. forma ephippiger (Rosa), and Criodrilus lacmmi 

 Hoffmstr.. a well-known European form. Neither fresh-water nor 

 littoral Oligochfeta throw much light on zoogeography, for birds 

 readily distribute the former (or their cocoons), and currents dis- 

 tribute the cocoons of the latter. Thus, Nais paraguayensis discovered 

 in Paraguay has been found in Lahore, and Enchtjtreens cdhidm is 

 found from Nova Zembla to Kerguelen Islands. 



Minute Structure of Tubifex.§ — Gertrude C. Dixon gives a fuU 

 account of the minute striicture of Tnhifex rivulornm, which abounds in 

 the mud of estuaries, often forming bright red masses. It is often 



=^ BiiU. Soc. Zool France, xl. (1915) pp. 100-1. 



t Mem. Indian Mus., v. (1915) pp. 137-8. 



X Mem. Indian Mus., v. (1915) pp. 141-6 (1 pi.). 



§ Liverpool ilar. Biol. Committee Memoirs, xxiii. (1915) pp. 1-100 (7 pis.). 



