Prof. Reid on the Vogmarus Islandicus. 473 



Though no doubt these spicular-looking bodies have the aspect 

 of crystals and retain their shape when dry, yet I believe that 

 they are composed of an animal texture similar to those fibres 

 that give the silver colour to the external surface and to the an- 

 terior surface of the iris in the Vaagmaer. These spicular-look- 

 ing bodies taken from all the situations above-mentioned rapidly 

 disappear under the action of aqua potassse, and when subjected 

 to the action of dilute muriatic acid under the microscope, though 

 they disappear, no evolution of gas is observed. In subjecting 

 those from the scales to the action of the diluted muriatic acid, 

 care must be taken to exclude any part of the scale itself, as 

 bullpe of gas are evolved when the substance of the scale is acted 

 on by the acid, — a result to be expected from their known che- 

 mical composition. Some of the bundles of these bodies procured 

 from the coloured layer of the sclerotic in the common dab looked 

 like those of the Vaagmaer in miniature. 



Immediately below these fibres and placed next to the cho- 

 rion or true skin there is a thin layer composed of a substance 

 without any distinct structure, having nuclei imbedded in it. In 

 this layer the external fibres are formed. On its surface and 

 between it and the bundles of external fibres are numerous spots 

 of black colouring matter, placed at short and in general regular 

 distances from each other, imparting, I believe, the leaden hue to 

 the bright silvery lustre of the external fibres. When this dark 

 matter is accumulated in greater quantities at any part, the sil- 

 very lustre may give place to the dark leaden hue. 



The next layer is the chorion or true skin, and may also be 

 divided into two parts : — 1. The more external of these contains 

 the tubercles on the skin already described, and constitutes a 

 minute network in the small interstices between these tubercles, 

 as may readily be made out by the aid of a pocket-lens, when this 

 layer has been detached from those above and below it. From 

 ten to twenty bands of a dense fibrous tissue may be seen ra- 

 diating from the circumference of one of these tubercles to those 

 surrounding it, and being united by cross bands form a close 

 network, the openings in which generally approach a round form. 

 In the tubercles the meshes of this network expand, become 

 united into a continuous membrane, and form their external co- 

 vering. This external covering of the tubercle becomes somewhat 

 thinner in the centre, bulges outward and forms internally a shal- 

 low rounded excavation with a well-defined edge, occupying about 

 two-thirds of its area. A texture differing in some respects from 

 true cartilage, but composed of hyaline substance with some in- 

 distinctly-defined corpuscles scattered through it, fills up this 

 shallow excavation, extends outwards beyond its margin to the 

 circumference of the tubercle, forms a small bulging or projec- 



