92 THE CANADIAN NATURALIST. [Dec. 



It should be remarked that the serpentine at Steinhag occurs, 

 not only repla^ng the sarcode in the carbonate of lime of 

 the Eozoon, but also forming layers over the limestone strata, 

 and moreover filling up large and small crevices and fissures, 

 which have nothing at all to do with the organic structure. 

 Especially worthy of notice are the plates of fibrous serpentine, 

 or chrysotile, often from five to ten millimeters in diameter, 

 which are found extending in unbroken lines through the compact 

 serpentine. 



The color of the serpentine presents all possible shades, from 

 blackish green, to the palest yellowish green tint. Where it has 

 been exposed to the weather, the serpentine has become of a pale 

 brownish green, and appears changed into gymnite. The different 

 tints are arranged in zones, and seem to mark different periods of 

 growth. The carbonate of lime which is interposed among the 

 grains of serpentine in the specimens from Steinhag, is either 

 distinctly crystalline, or apparently compact. In the first case, no 

 organic structure can be perceived ; thin sections of the crystalline 

 portions show only intersecting parallel lines; and in etched or 

 entirely decalcified specimens, no clear evidence of the fine 

 canal-system of the skeleton can be observed. These crystalline 

 portions often alternate with others which are compact and but 

 feebly translucent. In thin sections of these compact parts, the 

 rounded forms of the delicate tubuli are very clearly discerned, 

 provided the section is at right angles to them. In etched 

 specimens, viewed by reflected light, these tubuli are seen to 

 branch out in the form of tufts, exactly as described and figured 

 by Drs. Dawson and Carpenter. 



These branching and ramified tubuli rest upon the serpentine 

 granules, and seem by anastomosis to be connected with adjacent 

 groups. The diameter of these tubuli is from tooo to t!uo 

 millimeters. They are easily distinguishable from the delicate 

 groups of crystals, which are also sometimes found implanted in 

 the serpentine, by the nearly uniform thickness throughout their 

 whole length ; by their extremities, which are always somewhat 

 crooked ; and by their pipe-like form. The latter are never 

 ramified ; have a fibrous aspect ; and are always straight, and 

 terminate in a point. (PI. I., figs. 1, 2, 3.) 



Here and there are observed larger tubuli, which, so far as my 

 observations extend, are always isolated, and nearly or quite 

 parallel. (PI. I., fig. 1.) Their diameter is about tijo millimeters, 



