74 Rev. F. 0. Pickard-Cambridge on 



The palpus, in addition to great divergence in the form of 

 the base of the digital joint, presents also great differences in 

 the shape and development of two processes attached to the 

 palpal organs on the outer side. These are in the following- 

 descriptions termed respectively the " falciform process " and 

 the u lateral stylum." These processes are usually very 

 distinct in the majority of the Linyphini, but especially so in 

 species of the genera Leptyphantes, Bathyphantes, Tmeticus, 

 and Microneta. 



The epigynal process of the female is usually an infallible 

 specific character ; but in some cases the females of two diffe- 

 rent species present, if any difference, one that is almost 

 inappreciable, and therefore for practical purposes useless. 



A view of the process in profile with a strong simple lens 

 will usually suffice ; but often under a good light and a 1-inch 

 objective the form of the apex of the process viewed from 

 above furnishes a very distinctive character. 



It is not of course absolutely necessary that the identifica- 

 tion of all the species of this or any other obscure genus should 

 depend entirely upon the variation in form of these minute 

 portions of structure ; but when all other characters have 

 failed to give a satisfactory and reliable test of specific diffe- 

 rence, then this must be the last resort of the determined-to- 

 see-some-difference scientist, and, failing satisfaction here or 

 failing to define a difference which, though somehow or other 

 apparent, can yet neither be described with pen nor delineated 

 with pencil, then the obstinate irreconcilables must surely 

 be regarded as in a transition-stage, and must be left until 

 such time that under the influence of a wholesome self-respect, 

 aided by other kindly external influences, they get rather more 

 advanced, when perhaps some gimlet-eyed seer may be 

 enabled to detect some difference which he can not only feel 

 himself but can also see and describe in such a way that his 

 disciples may be able to feel and perceive as well. 



In the italicized portions of the following descriptions will 

 be found as a rule characters which are peculiar to the parti- 

 cular species under consideration. Those defined in the non- 

 italicized letterpress are almost all equally shared by one or 

 more species (sometimes by all) of the genus. 



It is necessary, however, to give these also if a thorough 

 and accurate description of a single species be needed. 



Leptyphantes zebrinus, Menge. 

 (PI. II. fig. I. 1,2,3,4.) 



Linyphia terricokt, Blk. 



Linyphia zebrina, Cambr. Spid. of Dorset, p. 182. 



Leptyphantes zebrwus, Sim. Les Arach. de France, p. 319. 



