F. P. SMITH ON THE BRITISH SPIDERS OF THE GENUS LTCOSA. 11 



the British families, omitting, where our knowledge enables us to 

 do so, any to which it is obvious that the specimen cannot belong. 

 Then, taking the more important characters, one by one, we 

 proceed to eliminate the families. Perhaps we notice that the 

 spider under examination has eight eyes. Immediately we can 

 draw a pencil through those families in which the eyes number 

 six. If its tarsal claws are three in number, the families 

 possessing but two claws are eliminated. In this way we soon 

 arrive at the end of our task, having, in the process, acquired a 

 good deal of useful knowledge. The family found, we can, by a 

 similar method, determine the genus and specie.-. 



I also advocate the omission from all papers, other than 

 original descriptions or monographic publications, of detailed 

 descriptions of specific characters furnished by organs of great 

 complexity. The structure of the palpus of the average male 

 spider, for example, is for practical purposes indescribable. At 

 any rate, a description, however minute its details, cannot 

 reasonably be expected to replace a carefully drawn figure of the 

 organ in question ; and if the latter exists, whence comes the 

 necessity for the former ? As a practical proof of the truthful- 

 ness of these remarks, read carefully the detailed description of 

 the palpus of some species of spider in any first-class monograph, 

 and then attempt to sketch the object described. A subsequent 

 comparison of the result with the author's own figure will be 

 sufficient proof of the inadequacy of language to convey to ones 

 mind the form of a complex object with which one is not well 

 acquainted The expert may be able to form a fairly accurate 

 mental picture from a good description, especially if this be 

 written by an author with whose style he is acquainted ; but with 

 all due deference to the expert, the needs of the beginner ought, 

 perhaps, to have first claim on our attention, for, unlike the 

 advanced student, he is not in a position to compile analytical 

 tables or reference lists for his own use, but is dependent for his 

 information upon those whose experience has enabled them to 

 do so. 



The question of synonyms next claims our attention. In the 

 case of common species it is altogether impracticable to give any- 

 thing like a complete list of references, and, in fact, no useful 

 purpose could be served by so doing. A very long list often 

 becomes an encumbrance, and seldom really justifies its existence. 



