446 Zoological Society. 



of the muzzle, throat, and under parts of the body are white, but 

 faintly tinted with yellow : on the back, and sides of the body, all 

 the hairs are of a deep gray or lead colour at the base ; and on the 

 under parts of the body, the hairs are indistinctly tinted with gray 

 at the base. The feet and tail are white. The ears are of moderate 

 size, furnished externally with deep golden-coloured hairs, and in- 

 ternally with whitish hairs. The moustaches consist of black and 

 white hairs intermixed. 



" The skull, when compared with that of Cricetus vulgaris, differs 

 in not having the anterior root of the zygomatic arch produced an- 

 teriorly in the form of a thin plate, which in that animal, as in the 

 Rats, serves to protect an opening which is connected with the nasal 

 cavity : the facial portion of the skull is proportionately longer and 

 narrower : in size there is much diiFerence, the skull of Cricetus au- 

 ratus being one inch and six lines in length, and ten lines in breadth, 

 measuring from the outer side of the zygomatic arches." 



April 23, 1839.— William H. Lloyd, Esq., in the Chair. 



A letter was read from Dr. Weissenborn, dated Weimar, Febru- 

 ary 19, 1839. It accompanied a female specimen of the Hamster 

 (Cricetus vulgaris), which he begged to present to the Society, and 

 related to some longitudinal, naked (or nearly naked) marks which 

 are observable on the hips of that animal. 



These marks. Dr. Weissenborn states, are found in every Ham- 

 ster, though usually hidden by the long fur which surrounds them, 

 and the common opinion of the furriers (who have to cut them out 

 and to repiece the skin) is, that they arise from friction. Being 

 situated over the hip-bones, and therefore more exposed than 

 other parts, the hair is worn whilst the animal is moving in its bur- 

 row. This is the opinion also of the earlier authors, but " is, how- 

 ever, erroneous, as remarked already by Dr. Sulzer, in his valuable 

 monograph on this species, published at Gotha in 1774. These 

 spots are visible the very moment the hair begins to grow, in the 

 naked young, and they are the very places where the growth of the 

 hair becomes first apparent. At this early stage of the animal's life, 

 they appear on the inner side of the skin, when viewed by trans- 

 mitted or reflected light, as two dark spots. When all the hair is 

 developed the case is reversed, and these spots appear paler than the 

 rest of the skin. Dr. Sulzer confesses himself to be quite ignorant 

 of the part which these peculiar spots act in the oeconomy of the 

 animal, and no subsequent author has explained the subject. I 

 imagine no person, after Sulzer, has turned his attention seriously 

 to it, but it is to be wondered that he was not more successful, being 



