OCR Text |
Show 885.] GERMAN RIVER-FROG. 667 Rana esculenta, var., Pfliiger, Arch. f. Phys. xxix. p. 67 (1882), and xxxii. p. 522(1883). Rana fortis, Boulenger, The Zoologist, xiii. p. 220 (1884). Diagnosis.-A large, strongly built form, with long hind limbs, the tibia proportionately longer than in the typical form ; inner metatarsal tubercle relatively small, elliptical, feebly prominent, compressed, measuring 2 to 4\ millim. in specimens in which the inner toe measures 9 to 15 millim. Olive, bronzy olive, or dull green above, with blackish-olive spots ; usually a pale green vertebral band ; no yellow on any part of the body ; hinder side of thighs olive, or greenish white marbled with dark olive. Vocal sacs grey. Dimensions. .<?• .2* millim. millim. From snout to vent 98 104 Length of head 30 32 Width of head 32 36 Diameter of the eye ! 8 8 Interorbital space 3 3 From the eye to the nostril 6 7 From the eye to the tip of the snout .... 13 15 Diameter of the tympanum 6 7 Fore limb 48 49 Hind limb 135 160 Tibia 42 50 Foot (from outer metatarsal tubercle) .... 44 51 Inner toe (from inner metatarsal tubercle) . 1 2 15 Inner metatarsal tubercle 4 4*5 Description.-The snout is normally broadly rounded, its length measuring half its width (from a transverse line passing on the anterior border of the orbits) ; in the extremes it measures two fifths or three fifths its width, as seen in the accompanying figures (Fig. 1, p. 668, where a and c represent the two extreme forms, fig. b the normal). The canthi rostrales are obtuse, and the loreal regions very oblique. The nostril is nearly equidistant from the eye and the end of the snout. The interorbital space is very narrow, measuring less than half the width of the upper eyelid, and usuallv more or less distinctly grooved longitudinally. The diameter of the tympanum equals half, or nearly half, that of the orbit. The hind limb being stretched forwards, the tibio-tarsal articulation reaches the eye or halfway between the latter and the end of the snout; there is no considerable difference in respect to the sexes. The legs or tibise being folded against the thighs and maintained at rio-ht angles to the vertebral column, their extremities overlap ; to ascertain this character with precision, it is necessary not to force the tibial extremities together, but to allow due space for the fleshy parts. In the typical R. esculenta, the extremities of the tibia either abut or are separated by a short interspace. This of course |