1 66 ON NEW AND RARE BRITISH ARACHNIDA. 



DIBLEMMA, gen. nov. 



Diblemma Donisthorpii, sp. n. PI. A, Figs. 713. 



Examples of both sexes received from Mr. Horace 

 Donisthorpe, by whom they were found in the Royal 

 Gardens at Kew. (For description sec postea p. 188.) 



Family DRASSID^. 



Drassus minusculus, L. Koch. 



A female of this species was received October 1907, from 

 Mr. W. R. Buttcrfield, by whom it was found near St. 

 Leonard's-on-Sea, and also an adult male in May, 1907, 

 from Rye Sandhills. 



Drassus lapidosus, Walck. 



Drassus Idpuiicolens, Walck. -Bl., Spid. G.B.I., p. 116; 

 Cambr., Spid. Dors, and Proc. Dors. F. Club, 

 Vol. XVI., p. 99, 1895. 



Drassus ctipreus, Bl., Spid. G.B.I., p. 114; Cambr., 

 Spid. Dors., p. 461, and Proc. Dors. F. Club, 

 Vol. XVI., p. 100, 1895. 



Drassus macer, Thor.-Cambr., Proc. Dors. F. Club, 

 Vol. XVI., p. 100, 1895, and Vol. XVIII., p. in, 

 1897. 



An examination of a considerable series of examples, com- 

 prising the three forms included in the foregoing synonyms 

 has led me to believe them to be only variations of 

 one species. There is at times considerable variation 

 in the development of the fakes, and in their dentition, as 

 well as in the absolute length of the palpi of the male, and 

 their different joints and structure but all endeavour to find 

 any reliable rule for the separation of species from these 

 variations seems to fail when brought to bear on a 

 lengthened series of examples ; nor does their colour- 

 variation seem sufficiently constant to help in their 

 separation. The variation in size of examples of the above 



