| OCR Text |
Show 608 MR. G. A. BOULENGER ON THE [June 16, Heads of Sana esculenta. R. esculenta ; it is also smaller compared with the inner toe, its length seldom equalling, and never exceeding, its distance from the subarticular tubercle of that toe. In the typical form the metatarsal tubercle is always more prominent, more or less strongly compressed, frequently crescentic in shape ; its length at least equals, and usually considerably exceeds, its distance from the subarticular tubercle. However, the length of the metatarsal tubercle is, like all characters, subject to a certain amount of variation ; the smaller variety of the typical R. esculenta, which occurs along the Rhine, has usually the tubercle larger than in tbe larger variety of the same form as occurring in Berlin and elsewhere, and to which Rosel's hana viridis belongs. It is a fact that a graduated series may be formed from the R. ridibunda with very small tubercle to the 11. esculenta with very large tubercle, and such a series is represented in the accompanying figures (Fig. 2, p. 669). The skin of the back and hind limbs is more or less warty, seldom |
