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XXII. — On the Femoral Plates or Scales of the Zootoca vivipara. 

 By J. B. Spencer, Esq. 



(Read January 15, 1851). 



In a work published some time since, a ' History of British Rep- 

 tiles,' by Professor Bell, a description is given of our two indigenous 

 lizards, Lacerta agilis and Zootoca vivipara; the former being a 

 beautiful reptile, more scarce than the latter, which is the brown 

 lizard of our heaths and commons ; they are both characterized by 

 being covered with scales or plates, varying greatly in size and 

 shape, some of them possessing a very curious structure, which I 

 propose to treat of in the present paper. The femoral plates or 

 pores described by Professor Bell, occur in a single row, upon the 

 under surface of each lower leg, running in the direction of its axis, 

 usually from ten to twelve in number; I will quote their description 

 from the work before-mentioned : — " The femoral pores, as they are 

 termed, exist also in all the family ; they consist probably of very 

 small follicular glands, each placed in a scale, the middle of which is 

 pierced by the opening of the follicle. In some the scale is very 

 little larger than the pore, and appears almost like a minute tube : 

 in others the scale is larger and triangular ; the use of these pores is 

 not known." In consequence of this latter statement, I was induced, 

 last autumn, to obtain some of these active little creatures, the 

 Zootoca vivipara, or common brown lizard, with a view to discover 

 the uses of these pores or plates. Upon examination with a sufficient 

 power I failed to realize the description of them given by Professor 

 Bell; no perforation could be found: on the contrary, the surface of 

 the femoral plates was produced into a semi-transparent process 

 or horn of a light yellow colour, differing in this respect from 

 the rest of the plate, and not possessing any discoverable perfora- 

 tions whatever. The average diameter of the plates is about 5V th 

 of an inch, the processes or horny parts varying from T Aoth to T §oth 

 of an inch. Some care is required in catching these very active little 

 creatures, for if any undue force is used, the processes above- 

 mentioned become broken or rubbed off, leaving the hollow cavity of 

 the plate exposed, and they then put on the appearance of perfora- 

 tions or .pores, and fully agree with the Professor's description 

 of them. Upon examining still further the internal structure of the 



