1910. Jackson — Rare Irish Spiders obtained in \^0(^. 145 



from specimens taken by Mr. Pack-Beresford at Portmarnock. 

 This form has not previously been recorded from Britain. 



The usual British form is the var. ina>itima of Kulczynski, 

 of which I also figure the palpal tibia. Intermediate forms 

 occur freely, the two being merely the extremes of a very 

 variable species. E. longipalpis^ Sund., is found in similar 

 situations, but seems to occur more freely in marshy inland 

 localities. E. atra^ Bl., and E. dentipalpis^ Wid., are ubiqui- 

 tous little spiders, and abound everj^where, being accomplished 

 aeronauts, whilst E. promiscua^ Camb., although widely 

 distributed, seems nowhere very common. So far it has 

 occurred most freel}^ in the Hastings district. 



There are two other British species included in this genus. 

 One of them, E. gratninicola^ Sund,, has just been removed hy 

 the Rev. J. E. HulP into the genus Tmeticus. Previousl}^ a 

 new genus, Erig07iidi2C7)i, F. P. Smith,^ had been created for 

 it. It is certainl}' not very closely related to the spiders now 

 under discussion. The other, Erigone spinosa^ Camb., differs 

 markedly from its present congeners in the sexual organs of 

 both sexes. It has recently been discovered as a British 

 spider on the shores of the Humbert 



EXPI^ANATION OF Pl,ATR 3. 



1. Erigone capra, Sim., , . . Left palpus from outer side. 

 la. „ ... Iveft palpus from below. 



lb. ,, ... Vulva of female from below 



2. Engove arctica, White (typical) . Left palpus from outer side. 

 2a. „ ... Right palpus from below. 

 2b. ,, ... Vulva of female from below. 



2C. ,, var. maritima, Kulcz. Tibia of left palpus from outer side. 



3. Erigone longipalpis, Sund. . . Left palpus from outer side. 

 3a. „ ... Right palpus from below. 

 3b ,, ... Vulva of female from below. 



4. Erigone atra, Bl., . . . Left palpus from below. 



4a. „ ... Tibia of left palpus from outer side. 



5. Erigone deniipalpisyVJ\(\., . . Tibia of left palpus from outer side. 



6. Erigone profuiscua, Qanih., . . Tibia of left palpus from outer side. 



7. Lophocaremivi straniineum, Menge Vulva of female froiu below. 



8. Lophocaremivi neniorale, Bl., . . Vulva of female from below. 



d. vi.y dens niedius; d. />., dens posticus. 

 Chester. 



1" The Genus Tmeticus." Transact, of Nat. Hist. Soc. of Northumberland, 

 Dnrhain. and Neivcastle-upon-Tync . New series, vol. iii., part 3, 1910. 



'^/ojtrnai of the Qitekett Microscopical Club, Ser. 2, vol. ix., p. 115. 



3Pickard-Cambridge. " On New and Rare British Arachnida." Proc. 

 Porset Field Club, vol. xxix., p. 75, 1908, 



