HERPETOLOGY OF THE GRAND DUCHY OF DADEN. 38? 



I observed a well-marked local variety in the marshy tract 

 where the following species occurs. It is the var. cinerea of 

 Koch,* described as : — " A smaller form, resembling a hybrid 

 from the slim character of its build. The protuberance at the 

 base of the fifth toe is normally developed, but the snout is more 

 pointed than with the typical form, thus recalling R. arvalis, 

 from which, however, it again differs decidedly by the normally 

 webbed feet, and by the shape of the protuberance. The indi- 

 viduals before me measure 40 to 45 millimetres from the snout 

 to the root of the hind legs. The colour varies between dark 

 ash-grey and brownish-grey, the lighter bars along the sides are 

 completely absent, and the entire upper surfaces (including head) 

 are covered with large and small deep-black spots. These are 

 not, as with the var. typica, continued along the hind legs in the 

 form of stripes, or in any case only appear indistinctly as such ; 

 the ear-mark is black, with grey spots. This form is rare, and 

 occurs on the peaty ground of the Schwanheimer wood, and 



elsewhere in the plain " It is a very constant form, the 



young resembling the adults of both sexes in their speckled 

 markings, and appears to be restricted to this locality. 



In consequence of its hardy constitution, this batrachian may 

 still be found at the approach of winter, when the others have 

 already retired. I have seen it up to October 21st and November 

 1st, and again as early as February 9th and 2nd. But these 

 dates are exceptional for the climate of Baden. The deposit of 

 the spawn is regulated by the state of the weather, and seldom 

 takes place before the first week in March. 



The proportion of the sexes seems to fluctuate according to 

 locality. On the whole, the males preponderate considerably, 

 though never to so large an extent as, for instance, with Bufo 

 vulgaris. 



3. R. arvalis, Nilsson. — The distribution of this interesting 

 batrachian is becoming defined with more certainty day by day, 

 in proportion as observers convince themselves of its " specific " 

 distinctness from the foregoing. Without enumerating the many 

 isolated localities, chiefly moorland and peaty districts, where 

 arvalis has survived, "a relic of the Glacial Period," up to the 



* Koch, ' Formen, &c, der Ecaudaten Batrachier,' p. 140. 



