RANA. 



293 



cess of squamosal as long as the posterior. Occipital 

 condyles entirely behind the articular extremities of 

 the upper jaw. 



Diapophyses of dorsal vertebrae more unequal in 

 length than in B. esculenta, the second once and a half 

 to once and two-thirds as Ions' as the last three. 



Tibia longer than the femur, nearly twice as long 

 as the tarsus. Terminal phalanges expanded at the 

 end, somewhat anchor-shaped. A single large bone 

 to the prgehallux. The sesamoid bone on the inner 

 side of the proximal extremity of the tarsus much 

 larger than in B. esculenta. 



Measurements of Skeleton (in millimetres). 



Habits. — Bana arvalis pairs in March or April, 

 together with or a week or a fortnight later than 

 B. temporaria, and after the breeding season leads a 

 terrestrial existence, being found in fields, meadows, 

 and bogs, in company with the common frog, although 

 as a rule more partial to damp localities. Numbers 

 of males hibernate under water. The voice is very 

 different from that of B. temporaria, and much 

 resembles that of B. agilis ; it may be rendered by 

 co, co, co, and has been compared to the sound of air 

 escaping from a bottle held under water. No fore- 

 sight is exercised in the selection of a site for the 

 deposition of the ova, which are often doomed through 

 the drying up of ditches or shallow puddles of rain 



