834 'Transactions of the Society. 



correct. He does not appear to have noticed the incurved edges 

 of the female carapace by which the eggs are held, as he figures it 

 merely as spoon-shaped, and states that the eggs are held in their 

 places by transparent threads. I have not been able to detect 

 these threads, but would not venture to deny their existence. He 

 also states that the dots on the cephalostegite are the openings of 

 glands ; if so, they would open inwards, but they appear to me 

 raised spots on the outer surface, and not openings at all. I do 

 not know whether he observed the polygonal markings on this 

 shield, but he does not figure them. He also contradicts Wagner's 

 assertion that bristles occur on this part of the body, and considers 

 that what Wagner took for bristles were parasitic fungi. I have 

 noticed that almost all my specimens had the cephalostegite and 

 sometimes other parts of the body covered Avith the frustules of a 

 diatom {Synedra), which at a casual glance might easily be 

 mistaken for bristles. Probably this was the cause of Wagner's 

 error. 



Two things would tend to prevent the earlier discovery of 

 Leftodora in Britain : first, its extreme transparency ; and second, 

 its habit of frequenting open and deep water, lor it is usually found 

 at a depth of three or four feet. A naturalist hunting for Ento- 

 mostraca, would probably only dip for them in the weedy shallows 

 where they mostly congregate, and would thus come away without 

 procuring a single Leptodora, even in a pool where they abounded. 

 Swimming in open water, the animal is of course exposed to the 

 attacks of fishes, and no doubt its transparency is then a great 

 protection to it. It would also serve to conceal it from any prey 

 on which it is stealing. 



Since its discovery at Olton reservoir, Leptodora has been 

 found in great abundance at Edgbaston Pool, another large sheet 

 of water in the neighbourhood of Birmingham, and in both pools 

 it was associated with Hyalodajphnia Kahlbergensis, also a new 

 discovery in this country. 



