AT THE MICROSCOPE. 45 



hope to see our members engage in. It is true, as remarked by 

 C. F. G. (see p. 52), that the weapon here is very different from 

 that of the Allantiis, but then so are its uses. Saw-flies have to 

 make incisions in the bark or leaves of trees wherein to deposit 

 their eggs, and therefore need powerful saws. Our Anwiophila 

 has merely, by piercing the tender skin of Caterpillars or 

 Spiders, to render them insensible till the larvae forming its 

 brood may be ready to feed upon them. The parts in A7}nnophila 

 compare much more closely with those in the Wasps — still, the 

 latter are specially weapons of defence. Some most interesting 

 observations on the habits of Ammophila will be found in West- 

 wood (Mod. Class. Insects, Vol. 2, pp. 205, 206). 



Acarus from Finch. (PI. 23, Fig. 5.)— It is to be regretted 

 that the exact species of Finch from whence it was procured is 

 not recorded, as from a scientific point of view this has real 

 importance. 



Birds must be subject to the complaint vulgarly called " Scotch 

 fiddle," or more politely " The Itch," to an extent of which there 

 could be no idea till the microscope revealed the number of such 

 parasites by which they are infested. I have many of these 

 Acari myself^ but think the present one is not amongst them. 

 There appear to be few birds not infested by at least two species; 

 it is a common thing to find three, and I possess examples of 

 jive different species, taken from some Water-bird. The one shown 

 here is a male; the females in this genus differ very greatly in 

 appearance from their mates. I find them most readily on the 

 pinnae of the principal wing-feathers, by holding the latter up to 

 the light ; here at times they may be found congregated in great 

 numbers. 



Hypopus muscarum. (PI. 24, Fig. i.) — The genus Hypopus 

 is probably a very large one. Through the kindness of various 

 friends (for the most part) I have had the opportunity of studying 

 numerous species. Some are sluggish in their habits, others run 

 very rapidly. How do they find their prey ? They have no 

 visible eyes, it is true; but many of their congeners are in the like 

 case. I think it likely to be through an exalted state of touch 

 in the long tactile set^e terminating the limbs, which represent 

 the whiskers of feline animals, whereby the latter can steal on 

 their prey through the deepest shades of night. They appear 

 to lurk under stones. S. J. Mclntire confirms this observation. 

 His remarks will be found in a paper headed " Notes on so-called 

 Acarelhis,'' in the Monthly Micro. Journal for Jan., 1874, p. i. 

 He found them in some " Cork-Cells," wherein were also 

 " Potato- Mites ^' and considers that the latter became transformed 

 into Hypopi! This appears to me most improbable. Both, 



