ON SOME RARE ARACHNIDS 49 



On some Rare Arachnids captured during igoy. 



By a. Randell Jackson, M.B., M.Sc. 



(Plate IV.) 



During the extremely unpropitious season of 1907 I have had 

 small time for, or opportunity of, doing outdoor work. Some of 

 my correspondents, however, have been more active, and by 

 their assistance a good many interesting species have been 

 got together. Three of these are new to the British fauna. 

 The first is Maro Falconerii sp. nov. This is a most minute 

 spider, and has been found by Mr. W. Falconer and myself in 

 Cheshire and Yorkshire. The second, Ischnothyreus velox sp. 

 nov., was discovered by Mr. R. S. Bagnall in a hothouse at 

 Alnwick. Subsequently I found it in a similar situation in 

 Chester, and Mr. Bagnall rediscovered it in one of the hot- 

 houses at the Botanical Gardens, Kevv. It is almost certainly 

 not indigenous, but seems to be establishing itself in suitable 

 situations throughout the country. Its small size and extreme 

 rapidity of foot favour its survival, but have probably delayed 

 for some time its detection and capture. The third species, 

 Bianor anescens (E. Sim.), has been found by Mr. W. H. 

 Bennett in Surrey. It is an Attid or leaping spider, and has 

 occurred in several European countries. No doubt it is a 

 genuine member of our fauna. 



After these three novelties, three other species claim the 

 chief interest. In each of these, one sex was previously known 

 in Britain, and the other is now recorded for the first time as 

 a native. The first of these is Maro nmmtus (Camb.). Mr, 

 Falconer had discovered the female at Huddersfield in 1905. 

 This year he found both sexes in the same locality, the male 

 being new to science. The second species is Gongylidiellum 

 paganum (Sim.) Both sexes of this interesting spider were 

 sent to me by Mr. D. R. Pack-Beresford, by whom they were 

 found near Bagenalstown in Ireland. The male had previously 

 been found near Huddersfield by Mr. Falconer, and the Irish 

 females were identical with one sent to me by that gentleman 



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