10 F. P. SMITH ON THE BRITISH SPIDERS OF THE GENUS LYCOS A. 



new, the author, unless he wishes to bequeath to future workers 

 a source of endless annoyance and dissention, should endeavour 

 to omit nothing from his description which could possibly be of 

 importance in the identification of the species in question. 



But let us now take, for example, the case of the genus Lycosa. 

 We have in this country eighteen species, and a full and detailed 

 description of any one of them might well occupy half the space 

 allotted to this entire introduction. Supposing, now, that a 

 beginner attempted to identify a specimen by the aid of a 

 monograph of the genus Lycosa written on these lines. 

 It is clear that all the family and generic characters would 

 be repeated in the description of each species, and although the 

 specific characters would, truly enough, be faithfully included, 

 they would constitute so small a percentage of the whole that 

 the inexperienced worker would, in all likelihood, be utterly 

 incapable of satisfactorily disentangling them from the pre- 

 ponderating verbose mass. Clearly, what is needed is a concise 

 comparison of the various species with the descriptions limited 

 to characters which are not common to the whole genus, and 

 which are thus likely to be of assistance, even if not of primary 

 systematic importance, in deciding upon the identity of a 

 specimen under consideration. I do not mean to suggest for a 

 moment that the student should be contented with any conclusions 

 which may be drawn from tables of differences or abbreviated 

 descriptions. To adopt such a course would be to court disaster, 

 and one must never lose sight of the real nature of tables, etc., 

 designed merely to facilitate the separation of genera or the 

 determination of species. They are, to use a figure of speech, 

 the "finders" on the main telescopes; we cannot, by their aid 

 alone, learn everything which is to be learnt, but yet without them 

 we feel, at any rate in our early studies, supremely helpless. 

 Analytical tables are now much in vogue, but, whilst admitting 

 their undoubted value, I personally prefer the use of abbreviated 

 descriptions as being far less mechanical and far more likely to 

 impress on one's memory the salient features of the various 

 species. 



I would strongly advise the beginner, whether he be working 

 from abbreviated or from full descriptions, to adopt a process of 

 elimination. Supposing we wish to determine the family to 

 which a spider belongs. The first step is to make a rough list of 



