92 SELECTED NOTES FROM 



retractor muscles {e.r. and r.r.^ Fig. 2). The structure of this 

 organ reminds one slightly of the mouth of a sheep-tick. The 

 feet are curious and possess a pair of claws (a cheese-mite has only 

 one), a pad, and two or more tenent hairs. Cheyleti are very 

 scantily furnished with hairs. It will be noticed that those on the 

 last joint of the fore-feet are much longer than on the last joints 

 of the other feet. Cheyleti use their fore-feet as feelers, having no 

 eyes, just in the same way as certain gnats use theirs ; consequently, 

 the hairs are longer to render them more sensitive. 



In Science Gossip. 1869, p. 5, some account of the Cheyleti and 

 their habits may be found. The following is a digest of that 

 paper : — Cheyleti feed on cheese-mites and other acari, which they 

 generally seize by the leg. They obtain nutriment by suction, 

 They are to be found on rotten wood, spiders' webs, etc., in old 

 cellars. They are active. They were first thought to be herma- 

 phrodite (but, as the contributor to the slide under observation 

 says, it contains two males and one female, this statement is doubt- 

 less false). At any rate, several generations of females produce 

 young without the intervention of the male, as Aphides do. The 

 eggs are laid in corners and kept from rolling about by being 

 secured by threads crossing in various directions. These threads 

 appear to be spun by the animal from the mouth (I doubt this, but 

 cannot detect any spinnerets). Cheyleti were first found by R. 

 Beck. H. M. J. Underhill. 



Head of Gnat. — I find the best way to mount these delicate 

 antennae is, after stupefying the gnat with chloroform, to sever the 

 head with a pair of fine-pointed scissors, and let it fall direct into 

 oil of cloves. After remaining there a few days or a wTek, I float 

 it at once on to a slide and mount in Canada balsam. A. A. 



Dolichopus (PI. IV., Upper portion).— I have given drawings of 

 a foot and an antenna of an allied species, Dolichopiis lo?igicornis, to 

 show some peculiarities of the genus. If the foot of the Doli- 

 chopus on the slide be examined, it will be observed that the ter- 

 minal joint of the tarsus is considerably thicker than any of the 

 others. Nevertheless, the difference in size is quite small when 

 compared with that of the tarsus of D. longicornis (see Figs. 

 A and B). There is another species, D. discife?-, which has tarsi 

 exactly intermediate in form to these two, even to the form of the 

 last joint but one. 



This enlargement of the last joint, which amounts almost to 

 grotesqueness in D. lo?igicor?iis, extends chiefly in one direction — 

 i.e., in the figure the greater diameter is shown ; if the foot were 

 seen from above, the last joint would appear but little broader 

 than the others. 



In some species of Dolichopus the other feet have peculiarities 



