375 



LEBER Tl A SEFVEI WALTER. 



By W. Williamson, F.L.S., F.R.S.E., and Charles D. Soar, 



F.L.S., F.R.M.S. 



{Read March I2th, 1918.) 



Plate 25. 



Among the species of Lebertia, two, L. giardinai Maglio * and 

 and L. sefvei Walter, f niay be readily distinguished from the 

 other members of the genus. This is due to the fact that they 

 have the genital area enclosed by the fourth pair of epimera. 

 The first of these was found in Italy and has the genital area in 

 the male completely surrounded, while in the female the rounded 

 inner posterior corners of the fourth pair of epimera come very 

 close together behind the genital area, but do not quite meefe.. 

 The second was found in Swedish Lapland, and differs from the 

 former in that the fourth pair of epimera are separated by a 

 narrow strip extending from the genital area to the rounded 

 posterior margin. It may also be noted that in L. giardinai 

 the spines of the palpi are pectinated, and that the inner ex- 

 tremities of the second pair of epimera end in a point, while in 

 L. sefvei the spines of the palpi are not pectinated and the inner 

 ends of the second pair of epimera are broad. 



The discovery of the Arctic form in Dartmoor brings the 

 number of the Britannic species up to twelve. 



L. sefvei belongs to sub-genus Hexalebertia and in length is a 



* Maglio, Rend. Ist. Lombardo, Ser. II. xli. 3 ; Atti. Soc. Ital. Sci. 

 Nat. Pavia, xlviii. 274-277, figs. 12-13. Monti, Atti. Soc. Ital. Sci. 

 Nat. Pavia, xlix. 59-61, figs. 51-54. 



t Naturunssenschaftliche U titer suchungen des Sarekgebirges in 

 Schwedisch-Lappland, Bd. IV. 598-60, PI. 9, figs. 11-13. (C. E. 

 Fritzes Bokforlags- Aktiebolag — Stockholm. ) 



