F. P. SMITH ON THE SPIDERS OF THE SUB-FAMILY ERIGONINAE. 13 



Cambridge's Spiders of Dorset, or from my own papers in the 

 Essex Naturalist, December 1902 and Nature Study, March 

 1904. 



The most useful method, generally, of examining a spider is 

 the following. A pomade-pot lid is nearly filled with methylated 

 spirit, and the specimen under observation placed in it. The 

 depth of the spirit should be sufficient to entirely submerge the 

 object, which is then examined by reflected light. For ordinary 

 araneological work no objectives will, as a rule, be required 

 higher than a quarter-inch, the two-inch and one-inch being 

 perhaps the most generally useful. It occasionally behoves the 

 arachnologist, desirous of discerning the exact form of some 

 obscure appendage, to distort various structures by means of 

 potash and pressure; but this method must be treated as the 

 exception, and not the rule. The legs and palpi of the smaller 

 spiders are usually sufficiently transparent to be mounted in 

 Deane's medium, after a few weeks in glycerine, without any 

 alkaline treatment and, thus prepared, are very suitable for 

 examination with dark-ground illumination. The form of the 

 caput, as seen either in profile, from above, or from the front, 

 is of great importance for purposes of identification and com- 

 parison, but for this purpose the required portion will have to 

 be cut from the body and mounted in a cell of alcohol. In the 

 few preparations of this kind which I have made, a loose mass 

 of cotton wool was placed in the cell — this keeping the object in 

 position against the cover-glass, and also preventing its moving 

 from the centre. Several cements have been recommended for 

 sealing spirit-mounts (e.g. see Journal of the Quekett Micro- 

 scopical Club, Ser. II., Vol. VI., p. 149) ; and although the student 

 of minute spiders may seldom desire to prepare permanent slides 

 of his specimens, it is as well to be acquainted with the technical 

 details of the process in case necessity should arise. 



For the storage of specimens I think the following method is 

 unrivalled for simplicity, neatness, compactness, and economy. 

 A wide-mouthed bottle of about four ounces capacity is taken, 

 a number of tubes two inches in length and about three-eighths 

 of an inch in diameter being ranged round the inside, and kept 



