33 



walking-stick, both in reaching to a greater distance and affording 

 a greater leverage. The rod may be made to screw off in two or 

 three lengths of 3 feet each, and can be conveniently carried in a 

 sheath. This smaller size of net has the great advantage of admitt- 

 ing conveniently a brass wire sieve, with a hoop about an inch deep 

 to fit into the ring of the muslin net, preventing weeds and other 

 coarse material from getting into the bag, but sufficiently open to 

 allow all the Microzoa to pass through. I find a sieve with a 

 ^-inch mesh very suitable. This protecting sieve requires to be 

 fitted tight into the mouth of the muslin net, so as not to fall out 

 when working, but sufficiently easy to be taken off when the contents 

 of the bag are turned out. For security, it is better to have the 

 sieve slung to the neck of the handle by a short cord. The size 

 of net is large enough to take in abundance of water with the 

 Microzoa, and is exceedingly well fitted to sweep and probe amongst 

 the vegetation, or to rake up the mud from the bottom, being at 

 the same time quite conveniently portable. The common Dutch 

 hoe has been used for the frame of the net, by piercing the inner 

 edge of the front plate with holes to sew the bag to. The remaining 

 part of the mouth of the bag is attached to the fork and back part 

 of the hoe, but is not so well adapted for working advantageously 

 amongst the vegetation. To work the net, simply sweep it through 

 the vegetation along the margin of the pond ; this done, remove 

 the sieve, invert the bag, and convey the contents into a white 

 saucer with water or wide-mouthed bottle, which w T ill, in most cases, 

 indicate whether there is anything worth further trial, though it 

 often happens that repeated trials afford good results in the same 

 place where they had failed to be seen by the first inspection. 

 The Ostracoda generally withdraw within their shells and become 

 motionless when alarmed, and are difficult to be seen in this state 

 among the debris of the gathering, but, where they do exist, more 

 or less of tbem come to the surface, and are readily detected in an 

 open vessel, but equally as well and more easily by examining the 

 contents of the net when the water is well pressed out. 



To have the full benefit of the gathering for Ostracoda. it is 

 necessary to take some of the mud, which in most cases can be 

 readily procured by scraping the sides or bottom of the pool with 

 the ring of the net. In order to reduce the bulk as much as possible, 

 all the impalpable mud should be washed thoroughly away till the 



water runs off clear. This can be done either in the working net, or 



c 



Fauna of Scot.— Crustacea I., Ostracoda. 



