272 EANID^. 



confined to Italy, the origin of these colonies is more 

 obscure than ever. 



4. Var. chinensis, Osb. (marmorata, Hallow. ; nigro- 

 maculata, Hallow. ; relnhardti, Ptrs. ; porosa, Cope ; 

 japonica, Blgr.). 



An Eastern form, ranging 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 ser- 

 vice in diagnosing these forms are the following : 



1. The development of the inner metatarsal tubercle, 

 whether large or small, blunt or compressed. The 

 length is taken alonsr the attachment of the tubercle 

 to the foot ; the length of the first toe, given for 

 comparison, is taken from the tubercle; and the length 

 of the latter is also compared to the length of the 

 cms or tibia measured in the flesh. 



2. The comparative length of the tibia to the thigh. 

 This is shown by pressing the two close together and 

 maintaining the tibia at right angle to the axis of the 

 body ; the tibial extremity, or heel, is then found to 

 overlap, to meet, or to fail to meet its fellow placed 

 in the same position. Only in Form 1 do they over- 

 lap, and this character alone differentiates it from the 

 three others. 



3. The presence or absence of short glandular folds 

 along the back, in addition to the dorso-lateral. The 

 presence of these folds differentiates Form 4 from the 

 three others. 



4. The presence or absence of bright yellow 

 pigment on the lumbar and post-femoral regions. 

 This pigment is constantly absent in Form 1, and 

 very seldom in Form 2. The character unfortunately 

 cannot be made use of with spirit specimens. 



By means of the first three characters we are able 



