376 MR. G. A. BOULENGER ON THE [JuDC 16, 



R. tigrina, Eicbw., R. dentex, Kryn., IR. maritima, Risso, R. his- 

 panica, Mich., vars. latastii, bedriagce, Cam., R.fortis, Boul., var. 

 perezi, Seoane, 



This is the largest and most widely distributed form, inhabiting 

 the whole of Europe with the exception of the North-western and 

 Central parts and li&\y. Western Asia as far east as North Baluch- 

 istan, Afghanistan, and Eastern Turkestan, and North Africa. As 

 being on the whole the least specialized form, i. e. departing less 

 from the normal pattern of the genus to which it belongs, it deserves 

 to rank first in the list, although the denomination oi forma typica 

 pertains to the next form, as having been first described under the 

 name of R. esculenta. 



2. Forma typica. 



=jB. esculenta, L., R. viridis aqiiatica, Ros., var. silvatica, Koch 

 (type examined). 



Northern and Central Europe, Italy, Russia. 



3. Var. LESSONiE. 



= var. lessoncB, part.. Cam. 



The habitat of this Frog, which in its characters is intermediate 

 between the preceding and the next, is still very incompletely ascer- 

 tained, specimens being known from England (Cambridgeshire and 

 Norfolk), the Rhine, the province Saxony, Piedmont and probably 

 other parts of Italy, and Malta. The British specimens are most likely 

 introduced from Italy. The opinion recently expressed by Bedriaga, 

 that Bell's R. scotica may belong to this form, is due to his having 

 misunderstood that author. The figure given in the first edition of the 

 'British Reptiles,' and which has been reproduced in the second 

 edition and copied by Ecker (Auat. des Frosches), is " taken from 

 a foreign specimen," and represents R. esculenta typica. Bell's 

 R. scotica is a synonym of R. temporaria. 



4. Var. NIGROMACULATA. 



=R. marmorata. Hallow. ; R. nigromaculnta, Hallow. ; Hoploba- 

 trachus reinhardti, Peters; Tomopterna jiorosa. Cope ; \&x.japonica, 

 Boul. 



The name japonica should be reserved for a species of the 

 temporaria-^TO\vp ; and R. esculenta, var. marmorata, Massal., is of 

 earlier date than R. marmorata. Hallow. I therefore adopt the name 

 nigromaculata, Hallow., which stands next on the list of synonyms. 

 This Eastern form ranges from Corea and Japan to Southern China 

 and Siam ; the exact western limits of its habitat have still to be 

 ascertained, and it would be particularly desirable to know whether 

 it anywhere comes into contact with or overlaps the area of the 

 ridibunda form. 



The principal characters which have proved of service in diagnosing 

 these forms are the following : — 



1. The development of the inner metatarsal tubercle, whether 



