INTRODUCTION. 7 



is not improbable that the water-frog, which Spallanzani 1 used in 

 his experiments on impregnation, was the R. maritima of Risso. He 

 says, one must not confound his frog with that which Rosel calls the 

 green water-frog ; the former being much smaller, without the three 

 dorsal golden-yellow stripes, and the spawning season (in Lom- 

 bardy) occurring during April and May. Rusconi 2 also describes 

 two varieties in Northern Italy. 



Rana temporaria, L., the brown or grass-frog, is so named from 

 the large black patch in the temporal region, i. e. between the eye 

 and the shoulder. While the separation of the preceding species 

 into several varieties does not seem to be well founded, it appears 

 that two distinct species have been included under the name of 

 R. temporaria. Millet of Angers 3 first described, in his Fauna du 

 departement de Maine-et-Loire, as 'grenouille rousse/ a species 

 differing from R. temporaria, and gave the species previously known 

 as E. temporaria the name of R. Jhnrivenfri*, f grenouille a ventre 

 jaune/ No further notice, however, was taken of this observation, 

 not even by Dumeril and Bibron in their ' Erpetologie/ Quite inde- 

 pendently Steenstrup 4 , in the year 1 846, pointed out that two frogs, 

 differing in structure and habits, had been confounded under the 

 name JR. temporaria; these he distinguished as R. platyrhinus and 

 R. oxyrltinw. Von Siebold 5 , and also Schiff 6 in part, have confirmed 

 these statements. My own observations lead me to a like conclu- 

 sion; I shall therefore distinguish two species, viz.: (i) Rana 

 temporaria, L., Rana platyrhinus, Steenstrup; (2) Rana oxyrhinv.%, 

 Steenstrup. 



Rana temporaria, L.; Rana platyrliinus, Steenstrup. The brown 

 grass-frog, Fig. 2, does not attain the dimensions of R. esculenta, L., 

 but is, however, always larger than R. oxyrhinus. The head is 

 somewhat broader than long, and the upper surface of the skull 

 is not grooved, as in R. esculenta, but is flat. The space between 

 the eyes is wider (according to Dumeril, equal to the width of the 

 upper eyelid, whereas in R. esculenta it is just two-thirds this 



1 Spallanzani, Versuche iiber Erzeugung der Thiere und Pflanzen. Leipzig, 1 786, 



p. 5- 



- Rusconi, Developp. de la Grenouille. Milan, 1826, p. 6. 



3 Annales des Sciences naturelles. Zoologie, IV Serie, Vol. IV, 1855, p. 368. 



1 Amtl. Bericht iiber die 24. Versammlung deutscher Xaturforscher in Kiel, 1846, 

 p. 141 ; Wiegrnann's Archiv, 1847, Vol. II, p. 341 ; Steenstrup, Oversigt K. Danske 

 Sel.sk. Forhandlgr., 1846, p. 92. 



5 Wiegmann's Archiv, 1852, Vol. I, p. 14. 



6 Annales des Sciences naturelles. Zoologie, IV Serie, Vol. IV, 1885, p. 368. 



