136 



plates, I could not perceive any secreting vessels or glandular struc- 

 ture within them, and therefore conclude that they serve some other 

 purpose than that of secretion. They may possibly serve (and their 

 shape favours the idea) to give the creature a greater mechanical 

 power of adhesion in certain cases ; and this view of the case has 

 been strengthened by the opinion of a very competent authority. I 

 have made a rough drawing (PI. XI. fig. 6), to give some idea of the 

 size and position of the plates, and have also mounted the skin of 

 the leg, showing the plates in situ, for the inspection of those mem- 

 bers who may be inclined to examine them. A perfect plate is 

 represented by a, fig. 7, and another in which the plate has been 

 removed by b, in the same figure. 



XXIII. — On the Scales of the Viviparous Blenny (Zoarcus viviparus). 

 By John Quekett, Esq. 



(Read January 15, 1851.) 



Mr. Spencer's observations on the femoral plates of Zootoca vivi- 

 para, have brought to my remembrance some notes made about ten 

 years since on the structure of the skin of the viviparous blenny, in 

 which I found that certain spots which had been described as circular 

 depressions were in reality scales ; and curiously enough, the descrip- 

 tion to which allusion has been made, occurs in another of Mr. Van 

 Voorst's series of works on Natural History, viz., Mr. Yarrell's ' His- 

 tory of British Fishes.' In speaking of the skin of this fish, Mr. 

 Yarrell states that " the surface of the body appears under a lens to 

 be studded with circular depressions." I found, however, on micro- 

 scopic examination, that these circular depressions, which are always 

 of a white colour, were due to the presence of small, round scales, 

 about one-twelfth of an inch in diameter, each having a minute spot 

 in the centre ; each scale, as shown in Plate XI. fig. 8, a, b, c, exhibit- 

 ing concentric and radiating markings. The scales are situated deep 

 in the cuticle, like those of the eel, and in some situations occur at 

 tolerably regular distances apart, but are rarely nearer together than 

 the twentieth of an inch. 



