584 SUMMARY OF CURRENT RESEARCHES RELATING TO 



distinguishing specific characters are distributed in an entirely haphazard 

 manner in the different specific groups, so that it is quite impossible to 

 show the phylogenetic affinities of the specific groups by any tree dike 

 arrangements. 



He infers that the present species of Peripatus are derived from a 

 single widely-ranging species roughly extending within the limits of the 

 present distribution, and that this species was highly variable, including 

 within the range of its variation all the different characters at present 

 exhibited by the whole genus. 



5. Arachnida. 



Regeneration and Autotomy in Spiders.* — S. Oppenheim confirms 

 some of the results recently reached by P. Friedrich. Terrestrial spiders 

 can throw off their limbs at the trochanter ; all the joints have a 

 strong regenerative capacity, but it is strongest at the preformed tro- 

 chanter plane. The regenerated limb, which differs from the normal 

 only in being smaller and lighter in colour, has not at first the power 

 of autotomy or of regeneration. Stimuli which would have provoked 

 autotomy on a normal limb had no effect during the first four days 

 after the moult which disclosed the regenerated limb. If during that 

 time a joint was cut through, there was no regeneration at the line of 

 amputation. At the next moult the (degenerated) remainder of the 

 limb was thrown off down to the line of normal autotomy. Some time 

 is necessary to allow the new limb to attain the full differentiation 

 needed for normal autotomy and regeneration. 



Friedrich | could not find evidence of autotomy or regeneration in 

 Aryyroneta aquatim, and he inferred that this was because there was no 

 need for it. But Oppenheim, like 0. Weiss,f finds experimental evidence 

 of both autotomy and regeneration as regards the foremost and hindmost 

 appendage. 



British Spiders.J— F. P. Smith records, from the Isle of Wight, 

 Toxem formicarius, one of our rarest, handsomest, and most interesting 

 spiders, whose presence in Britain has hitherto been attested only by 

 several isolated records extending over three-quarters of a century. The 

 mature male might be mistaken for a red ant. A male and female of 

 Tarentvla nemoralis — now for the first time recorded from Britain — were 

 taken in the Bexhill High Woods, and the very rare Lycosa agrestis was 

 found in the Isle of Wight. 



Notes on Pseudoscorpions.§ — Edv. Ellingsen reports on a collection 

 of pseudoscorpions, mostly British, made and partly determined by 

 H. Wallis Kew. He notes that Obisium {Roncus) cambridgii has a 

 galea, and should be referred to the genus Ideobisium. He describes 

 Chelifer Tcewii sp. n. from Cape Colony, Obisium maritimum Leach from 

 British coasts, and some other interesting forms. 



* Zool. Anzeig., xxxiii. (1908) pp 56-60 (3 figs.). 



t Arch. Entwickmech., xx. (1906). t Op. cit.,xxiii. (1907). 



X Journ. Quekett Micr. Club, 1907, pp. 177-90, 1 pi. 



§ Tom. cit., pp 155-72. 



