SETTING AND PRESERVING ARACIINoKda AND ACARI. 317 



fresh water, to extract the sak, which would soon destroy them by at- 

 tracting moisture; tliey are then to be phiced in a crawhng posture, 

 and the parts of the mouth are to be displayed by means of pins un- 

 til dry ; they will then remain in that position. The more minute 

 species must be dried, and afterwards stuck on paper with giun-water, 

 in ditierent positions. Those of Mi/riapoda are to be killed by immer- 

 sion in spirits, and afterwards stuck with a pin on the right side. 



Crustacea and Mt/riapoda arc kept in cabinets lined with cork, to 

 which they are aftixed with pins; or in boxes loose: the former me- 

 thod is best, as they can then be moved from one place to another 

 without trouble or risk. 



AUACIIXOIPA AND ACART. 



The habitations of the animals of this class are fully described in 

 the account of the genera, — further observations on this point will 

 therefore be unnecessary. 



Method of prcsemhig. — Mr. Donovan has observed, " To determine 

 whether some species of Spiders could be preserved with their natu- 

 ral colours, I i)ut several into spirits of wine ; those with gibbous bo- 

 dies soon after discharged a very considerable quantiy of viscid matter, 

 and therewith all their most beautiful colours ; the smallest retained 

 their form, and only ajipeared rather paler in the colours than when 

 they were living. 



" During the course of last summer, among other Spiders, I met 

 with a rare species; it was of a bright yellow colour, elegantly marked 

 with black, red, green, and purple. By some accident it was unfortu- 

 nately crushed to pieces in the chip-box wherein it was confined, and 

 was therefore thrown aside as useless ; a mouth or more after that 

 time, ha\ing occasion to open the box, I observed that such parts of 

 the skin as had dried against the inside of the box retained the origi- 

 nal brightness of colour in a considerable degree. To further the 

 experiment, I made a similar attempt, with some caution, on the body 

 of another spider {Aranca Diadcma), and though the colours were not 

 perfectly preserved, they appeared distinct. 



" From other obser\'ations I liud, that if you kill the spider, and 

 immediately after extract the entrails, then intlate them by means of 

 a blow-pipe, you may preserve them tolerably well : yovi must cleanse 

 them on the inside no more than is sutiicient to prevent mouldiness, 

 lest you injure the colours, which certainly in many kinds depend on 

 some substance that lies beneath the skin." 



The best preserved specimens that 1 have seen are those where the 

 contents of the abdomen have been taken out and filled with tine sand. 

 I liave preserved several in this way, and tind it answer the purpose. 



