1891.1 



RACES OF RANA ESCULENTA. 



381 



above, uniform or spotted with black ; hinder side of thighs 

 handsomely marbled with black, and usually v\ith more or less of 

 bright yellow pigment ; vocal sacs white or feebly pigmented. 



The range of variation of the somewhat complex assemblage which 

 I have endeavoured to define as the typical form is very great indeed 

 and forms a gradated series leading from the form ridibunda to 

 the form lessonce. 



I must confess that the line drawn between the latter and the 

 typical form appears to me arbitrary, and that my arrangement is 

 open to this criticism, that there is altogether a greater a.tiount of 

 difference between the two extremes of tlie series than there is 

 between the extreme in the lessonce direction and the form lessonae 

 itself. The true typical R. esculeiita, as figured by Rosel, is pretty 

 well in the middle of the series: the extreme specimens with small 

 inner metatarsal tubercle are from France, Corsica, and Italy ; whilst 

 the opposite extreme obtains in the specimens from Basle and Vienna. 



S 

 2 

 c? 



? 



5 



d 



2 

 2 

 d 



2 

 2 

 6 

 d 

 2 

 2 

 d 

 2 

 2 

 2 

 2 

 ? 

 d 

 2 

 d 

 2 

 d 

 2 

 Proc 



Measurements. 



1. 2. 



St. Malo 73 33 



72 34 



Paris 69 35 



„ 84 38 



Brussels ,54 28 



„ 66 33 



Basle 61 2/ 



,y 56 26 



., 67 31 



„ 63 29 



Geneva 61 31 



„ 51 2") 



78 39 



70 36 



Copenhagen .... 68 30 



.... 63 28 



LoUand 85 35 



„ 80 36 



Berlin 68 32 



86 35 



Warsaw 87 42 



„ 80 37 



Neusiedl Lake . . 81 43 



..80 40 



Vienna 64 30 



„ 50 24 



Nice 54 2 7 



. „ 80 41 



Rivoli 65 32 



66 32 



ZooL. Soc— 1891, No. XXVI. 



