8o 



Records of the Indian Museum. 



[Vol. VI ^ 



Table i shows the distribution of the characters distinguishing 

 S. stoliczkae from 5. severzovi among eight groups: col. i gives the 

 group; col. 2, the average total length of the members of the group 

 in millimetres ; col. 3^ average of the relation of total length to 

 maximum bod5^-height ; col. 4, average of the relation of head- 

 length to the diameter of the eye. In cols. 5, 6 and y , E repre- 

 sents that the group belongs to the Ssewerzoff type for this 

 character, T that it belongs to the Stoliczka type, ET that the 

 group contains individuals of both types : col. 5 deals with the 

 same proportion as col. 3 ; in Ssewerzoff's type the relation is 5"4 

 and less, in Stoliczka's 5 •5 and more : col. 6 is the same proportion 

 as col, 4; Ssewerzoif's type is 4*5 and below, Stoliczka's 4*6 and 

 above : col. 7 represents the relation of the anterior end of the 

 mouth-cleft to the lower margin of the orbit; in Ssewerzoff's type 

 the former is on the same level or above the latter, in Stoliczka's 

 it is below the latter. 



Table I. 



The question then arises whether the two species can be 

 separated on the differences in the shape of the head alone (charac- 

 ter c), and as a complete series of gradations between the two 

 extremes occurs (pi, iii, figs, i, 2 and 3) it does not appear to the 

 present writer that this can be done. 



If all the specimens from one particular narrow locality are 

 brought together it will be found that one head type or the other 

 predominates. One type ma^^ be present to the exclusion of the 

 other but intermediates are also generally present and occasionally 

 the opposite type as well. The specimens from Guru (D. i and 2) 

 are of Stoliczka's type 4 specimens, intermediate i; those from 

 the Chumbi group consist of Ssewerzoff's t3^pe only ; those from 

 Kang-ma (K. i) of Stoliczka's only. Alcock's specimens from Oi- 

 kul, Little Pamir, of Ssewerzoff's 3, intermediates or Stoliczka's 3. 



There is another character in which very considerable variation 



