July 1, 18(30.] 



SCIENCE-GOSSIP. 



157 



like the beak of a parrot, whence its name is derived. 

 It lias been found in a pond on Blackheath between 

 the months of April and September, but whether 

 discovered elsewhere we have no knowledge. 



The large Water-flea {Daphnia scheefferi). 

 This is larger than the common water-flea, and the 

 eye is smaller in comparison. It is also found in 

 ponds, but less commonly. Dr. Baird collected it at 

 Bexley Heath and Norwood Green. 



The spineless 



& -- y W ATER-FLE A 



[Daphnia vefula), 



which has a smaller 

 beard than the 

 common water- 

 flea, and is desti- 

 tute of the tail- 

 like pine. It is a 

 common species in 

 similar localities 

 around London. 



The reticu- 

 lated Water- 

 flea {Daphnia 

 reticulata). In 

 his species the 

 shell is covered 

 with a network of 

 hexagonal cells. 

 The tail is very 

 short, and a little inclined backwards. It is by no 

 means uncommon, especially at Highgate and Bat- 

 tersea, during summer and autumn. 



Fig. 150. Daphnia pulex {male). 



nearly round. The tail is short and blunt, but it is 

 altogether larger than the reticulated water-flea. 

 It occurs in the same localities. 



Fig. 152. Daphnia vetula (female). 



The Long-spined Water-flea {Daphnia mu- 

 eronata\ — This species may be easily known by the 

 front edge of the shell being perfectly straight, and 

 the long pointed spine at the lower extremity. It 

 is not a common species, but has been found in 

 ponds about Isleworth &c, in the autumn. 



The characters we have given, are merely those 

 which would be recognized at once. There arc other 

 features whereby one species is separated from 

 another, but it is hoped that the figures and points 



Fig. 151. Diphniu sclttefftri (female). 



Fig. 153. Daphnia reticulata 

 (female). 



Fig. 154. Daphnia mucron da 

 (female). 



' The rounded Water-flea {Daphnia rotunda). 

 As its name indicates, the shell of this species is 



of difference indicated, will be a sufficient guide for 



the discrimination of the several species. 



C. 



