182 HALF-AN-HOUR AT THE MICROSCOPE. 



ing at a rather wide angle. From the sudden clutching of these 

 organs, I have no doubt that they, too, are for seizing prey, and 

 very effective instruments they must be, for the joints bend down 

 towards each other, and the long rows of spines interlacing must 

 form a secure prison, like a wire cage, out of which the jaws pro- 

 bably take the victim, when the bending-in of the antennas has 

 delivered it to the mouth. 



" But these well-furnished animals are not satisfied with fishing 

 merely at one station. As I have said above, they climb nimbly 

 and eagerly to and fro, insinuating themselves among the branches 

 and dragging themselves hither and thither by the twigs. On a 

 straight surface, as when marching (the motion is too free and 

 rapid to call it craic/iiig) along the stem of a zoophyte, the crea- 

 ture proceeds by loops, catching hold with the fore-limbs, and 

 then bringing up the hinder ones close, the intermediate segments 

 of the body forming an arch, exactly as the caterpillars of geome- 

 tric moths, such as those, for example, that we see on gooseberry 

 bushes do. But the action of the crustacean is much more ener- 

 getic than that of the caterpillar ; indeed, all its motions strike me 

 as full of vigour and energy. 



" I have seen the large red species swim, throwing its body 

 into a double curve like the letter Sj with the head bent down 

 and the hind limbs turned back, the body being in an upright 

 position. It was a most awkward attempt, and though there was 

 much effort there was little effect." 



I have no doubt members would be able to keep these crusta- 

 ceans in an aquarium, and would find very interesting material for 

 study in watching their life-habits and especially their develop- 

 ment. A member at Fareham tells me that specimens appeared 

 occasionally in water drawn by a fresh-water pump — an estuary of 

 the sea, perhaps— a quarter of a mile from the pump, but evi- 

 dently having underground communication with the basin whence 

 the soft water came. I have found C. linearis abundantly in tidal 

 pools at Ryde, Isle of Wight. 



Haematopinus suis. — This specimen appears to have been 

 prepared by simply soaking for a time in turpentine and then 

 mounting in balsam. This plan was recommended long ago by 

 Cornelius Varley in the London Physiological Journal, Vol. I., 

 184 1, p. 31. By adopting it, important details of internal struc- 

 ture, destroyed by the plans most in vogue now, of steeping in 

 liqzi07- pofassce, may be beautifully retained. I allude in the 

 present instance to the supra- and sub- oesophagal ganglia and 

 nerves proceeding thence to the eyes, the antennae, and the oral 

 organs. The female differs little outwardly from the male, except 

 for the cleft vulva. 



