STUDY OF VARIATION IN THE RACES OF ZYGAENA FILIPENDULAE, L. 127 



remainder of the wing red ; as a rule some dark streaks exist between 

 the cell and the dorsal margin and a dark spot exists inside the cell; 

 individuals in which they are absent, like those figured by Hiibnerand 

 Boisduval, are scarce. Collecting has not been carried on fully 

 enough in Piedmont to determine exactly where races answering that 

 description are to be found, but from the specimens of various localities 

 sent to me by Signor Gianelli of Turin and from the few I have 

 collected myself near Turin and near Acqui it would seem as if 

 medicaginis was a very common and diffused form from the Alpine 

 valleys to the hills of the Upper Po basin. Thence it is met with on 

 the Apennine in the whole of the " zone of melanism " I have described 

 when dealing with stoechadis in general and it predominates here and 

 there. For instance, Querci and I have found on the Futa Pass road, 

 at La Traversa and Covigliaio, m. 900, in northern Tuscany, a race 

 which by the extent of the primary pattern corresponds to the des- 

 cription given above and which does not differ from Piedmontese 

 specimens either in sizb or colour, being smaller than etmsca and of a 

 pure bright indigo (not greenish), larger and more saturated in tinge 

 than inontiva,,a. In this series 20% of the males and 30% of the 

 females are six-spotted. It is very likely that Illyria, Istria and 

 Dalmatia also produce medicaginis in some mountain localities. 



Race stoechadis, Borkhausen (Rheinischex Magazin, i., p. 628 

 (1793)). Those readers who might be interested in the unhappy origin 

 of the name stoechadis, Borkhausen, I am obliged to refer to 

 Oberthiir's interesting historical notes in the Etudes de hep. Coinp., 

 iv., pp. 527-538. I must limit myself here to quoting Borkhausen's 

 original description drawn from a figure published by Hiibner in his 

 Beit rage zitr Geschichte der Schmetteiiinge, ii., pi. III., fig. 0. :• " The 

 whole of the wings of a bluish-green, superior ones with six red spots, 

 inferior with two or three and erasion of the base red . . ." The 

 localities given are " Languedoc and Piedmont," but the latter alone 

 stands good, because the former is a mistake due to the fact that 

 Z. lavandulae, Esp., is mixed up in the description. Individual forms 

 roughly answering this description are, of course, to be found almost 

 anywhere in Piedmont, but the creation of the name medicaginis for 

 less melanic ones has limited stoechadis, as the name of a race, to 

 those localities in that region in which the majority of male 

 individuals can be described as having the hindwings entirely darkened 

 by the primary pattern, except a red spot at the end of the cell and 

 some marked red rays at their base. As in medicaginis, the exact 

 localities of the race answering this description cannot as yet be made 

 out for lack of material. Probably it will, as a rule, be found more 

 frequently at higher altitudes than medicaginis, and especially in the 

 Alps. Many of the specimens collected by Gianelli at Susa, m. 500, 

 and at the village of Valdieri, m. 750, belong to this form, but 

 whether they predominate I do not know ; so does the only 

 individual of this species which I have ever found at the Baths of 

 Valdieri, as high as m. 1375. With medicaginis this race extends 

 along the main range of the Apennines to northern Tuscany, and it is 

 found, generally at high altitudes, all over the " zone of melanism " 

 in the localities where it is not replaced either by inedicaginis or 

 aterrima described in the next paragraph. I possess a series collected 

 by the Quercis at Palazzuolo di Romagna, m. 700, which quite agrees 

 with the race of Piedmont in every respect ; another from the 



