On some littU-hnown British Spiders. 1G3 



EXPLANATION OF TLATE IX. 



Fif/s. 1, la, lb. Choanomphnlusjaponicmperstriatidas, subsp. n., X 8. 



Fig. 1 c. Sculpture of same, x 10. 



Figs. 2, 2 a, 2 b. Choanomphahis /nponiciis, sp. n., X G. 



Fir/, 2 c. Sculpture of aauie, X 9. 



Fif/s. 3, 3 a, 3 b. Planorbis {Gi/ra'dus) biwa'eiisis, sp. n., X 4. 



Fiff. 3 c. Sculpture of same, x 8. 



Fiff. 4. Valvata biwaensis, sp. u., X 4, 



Fig. 4 a. Sculpture of same, X 8. 



Figs. 5, 5 a. Valvnta annandalei, sp. n., X 4. 



Fig, 5 b. Sculpture of same, X 8. 



Figs, 6, 6 a. Lithotis japonica, sp. n., X G. 



XT. — On the Nomenclature and Idintity of some littJe-hnoioti 

 British Spiders. By A. Randell Jackson, M.D., D.Sc. 



During the l:ist two years the Rev. 0. Pickard-Cambridg-e 

 lias kindly allowed nie to examine the actual types of a 

 number of little-known British spiders. For the most part 

 these were described many years af^o, when microscopes 

 were new or little-known instruments. Many of these 

 s[)iders had never been recorded since ; but there was no 

 doubt that several of them had been redescribed under other 

 names when the use of microscopes became more o-eneral. 



I here publish the result of these iuvestigations as far as I 

 have gone. I had hoped to have examined all the species on 

 the British list which were unknown to me, but circumstances 

 will not now permit this. I hope, however, to linish this 

 investigation at some future date. 



For iialf a century Mr. Pickard-Cambridge has laboured 

 in the field of arachnology, and his collection contains nearly 

 all the species hitherto recorded as British. Hence the great 

 kindness he has sht)vvn me in allowing me to examine these 

 types lias put me in possession of many facts otherwise 

 inaccessible. I here thank him for this and for all the 

 innumerable otiier kindnesses he has done me. 



In my previous papers on the genera Microneta and Par- 

 rhomma I accounted for many of these half-forgotten species. 

 I here continue the work, and have now, save for about a 

 dozen species, finislied the great family Argiopidas, which 

 contains considerably more than half of the British spider- 

 fauna. 



I may say that I have not gone into any ancient questions 

 of nomenclature, but have started from the basis of 

 Mr. Pickard-Cambridge's ' List of British and Irish Spiders,' 

 published in 1900. 



