188 SELECTED NOTES FROM 



embryos of all sorts, etc., that would settle on the polypidom, and 

 so cause injury to the body politic^ "move on." On carefully 

 reading Mr. Nicholson's remark, it will not be understood that the 

 eel, Afigiiillula (T. W.) and Aviailariiim died together, the latter 

 becoming detached after death from exhaustion, but only that on 

 attempting to mount the object, the Anguillula slipped from the 

 grasp of " X 249," his life having come to an end, I suppose, 

 from the strong dose of poison administered in the guise of 

 " moimting fluids Most of the Polyzoa have these processes, 

 their soft parts are continuous with the soft parts of the zoophyte 

 to which they belong, and correspondingly nourished. Some 

 Polyzoa have, instead, vibracula^ or bristles, which in life sweep 

 constantly over the surface. Molly with her broom always at 

 work, you see, to keep things clean and tidy. In some instances, 

 both forms are found on the same polype, in others only one ; 

 they furnish a valuable help in classification. The pedicellaria of 

 the Echini and many star-fishes (see Herapath in Quart. Jour. 

 Micro. Sci., 1865, p. 175) are precisely analogous. 



TuFFEN West. 



A paper, with a plate of illustrations, on Avicularia will be 

 found in Lon. Micro. Jour., 1854. 



A. Nicholson. 



Atax, a Water- Mite found on a Iivi?tg Gnat. — Mr. Alfred 

 Atkinson (President) circulated a slide of above, which induced 

 the following remarks from Mr. Ball, a member well up in Acarea : — 

 *' Mr. Atkinson's mites are particularly interesting from the fact of 

 their having been found upon a gnat. They certainly were " fish 

 out of water," since in the first place they are not parasitic mites at 

 all, nor are they acari as stated on the slide. They are the young 

 of a species of Atax^ a mite which swims freely in the water. The 

 most familiar example of the genus is a beautiful scarlet mite, 

 which may often be seen spinning its way through clear water in 

 ponds, etc. I should like to know whether the gnat was a dead 

 one picked up on the surface of some water." To this Mr. Atkin- 

 son replied. 



Hogg says of ^^ Hydi-achnidce'^ \ — "In their young state they 

 attach themselves parasitically to aquatic animals." These mites 

 were certainly parasitic when I found them. They entirely covered 

 the posterior portions of the body of the insect, which was taken 

 alive, and lived under an inverted wine-glass several days. I'hey 

 are young mites, as they have not yet developed the fourth pair of 



