1866.] KING AND EOWNET ** EOZOONAL EOCK." 193 



tained by Rhizopodists, it never could have presented sucli appear- 

 ances ; the calcite, and not the serpentine, would have exhibited the 

 lineated and asbestiform structure. 



Considering that there is an allomorphic variety of serpentine 

 known as chrysotile, which possesses characters identical with those 

 of the so-called " proper wall," we feel ourselves warranted in assu- 

 ming that this part is a layer of the latter mineral. 



Moreover, not only does the serpentine become asbestiform, but it 

 is frequently found changed into a white flocculent substance*, which 

 takes the place of the "proper wall" — occurring on the surface of 

 the granules as a crust of varying thickness, and frequently inter- 

 mixing with the calcite of the skeleton f. Instances have occurred 

 to us of the serpentine alternately assuming both kinds of structure, 

 as shown in fig. 3, Plate XI Y., which represents a thin transparent 

 section, seen by transmitted light, of three granules with an irregular 

 notched border : the projections consist of incipiently chrysotilized 

 serpentine, and the interspaces or notches of flocculent matter. 



The substance under notice has generally a loosish granular tex- 

 ture ; and often it is compact like starch ; it is also rudely lamellar 

 or prismatic. Occasionally we find it colourless and pellucid, like 

 chalcedony, and having no appearance of structure under a low 

 power; but when examined with an object-glass magnifying 350 

 diameters, it is seen to be fibrous. In short, one of our specimens 

 of Ophite from Lisoughter shows the surface of a granule of serpen- 

 tine imperceptibly passing into the asbestiform layer, and this part, 

 here and there, gradually changing into the flocculent crust ; while 

 closely adjacent there occurs a mass of the flocculent substance en- 

 closing, or rather 'passing imperceptibly into, asbestiform crystalliza- 

 tion, the crystals being fine, long, and well developed. 



The granules are not always furnished with an asbestiform layer, 

 or a flocculent crust ; for highly polished, and consequently trans- 

 lucent specimens, which have not been submitted to decalcification, 

 occasionally show them wholly devoid of any covering, their surface 

 being in immediate contact with the " calcareous skeleton ; " and in 

 decalcified specimens we have also seen granules with surfaces' quite 

 smooth, and appearing as if nothing had ever been attached to them. 



Reverting to the cases which show the fibres or aciculi of the 

 asbestiform layer standing apart, attention may be first directed to 



* For the sake of brevity and distinction, we propose to name this substance 

 Jlocculife— not, however, raider the idea of its being a new mineral. It is our 

 present impression that flocculite is merely an allomorph of serpentine ; we are 

 quite ready, nevertheless, to accept it as a chemically different, though closely 

 related substance. Saponite, pseudophite, and some other allied minerals, are 

 similarly structureless. Aphrodite, except that its silica and magnesia are in 

 different relative proportions to those prevailing in serpentine, appears to come 

 nearest to flocculite. The gran alar mineral occurring as a bed in the crystalline 

 limestone at Grenville, and which Dr. Sterry Hunt has identified with pyrallo- 

 lite (Geology of Canada^ 1863, p. 470), may be identical with it. 



t In thin transparent sections, examined by transmitted light, the serpentine 

 has a metallic appearance resembling brass. Very minute particles of unchanged 

 serpentine may be detected by this character, intermixed, with the flocculent sub- 

 stance, both being interspersed amongst the calcite of the skeleton. 



