EXPLANATION OF THE PLATES. 



passes through the Bakie Loch, showing that the recent deposits of marl in that 

 lake rest upon the diluvium of Strathmore. 

 Fig. 2. represents a canoe, found in peat overlying this marl in the Loch of Kin- 

 nordy, — a lake about 6 miles N.E. of the Bakie : see note, p. 87. — and for the 

 deposits in that lake, p. 86. 



Fig. 3. Supposed section of the deposits in the Bakie Loch : for a description of 

 these, and of the organic remains contained in them, &c. see pp. 74, 76, 77, 79, 81, 



83. and Appendix I. 



Plate XL 



A map of that part of Forfarshire, in which the principal deposits of shell-marl are 

 situated ; showing that this marl is confined to the old red-sandstone formation, 

 and the series of inferior gray, micaceous sandstone, shales, &c., with their asso- 

 ciated trap-rocks : see p. 1 and 79. 



Plate XIL 

 Recent and fossilized Charae ; from the Bakie Loch and other marl-lakes in the county 

 of Forfar. 



Fig. 1. a. Gyrogonite, or fossilized pericarpium of Chara, found in the tufaceous lime- 

 stone or rock-marl of the Bakie Loch — of the natural size : p. 79, 91. 



b. The same magnified 20 diameters, the upper end being placed downwards. 

 It consists in general of the empty integument completely replaced by carbonate 

 of lime : p. 92. 



c. Lower end of ditto, to which the stem was attached : p. 92. 



d. Upper end of ditto, to which the stigmata were attached. 



e. Nut, sometimes found within the integument b; but consisting of an unfossilized 

 brown membrane ; the end to which the stigmata were attached placed down- 

 ward. The small fibres appended may be the styles ? p. 92. 



f. represents the nut, within a portion of the fossilized integument : p. 92. 



g. One of the spiral valves of b. These are easily separable in the Bakie Gyro- 

 gonite, as in those found in the ancient fresh water- formation : p. 92. 



h. View of the interior of d, 



i. Section of one of the valves of the integument, showing their quadrangular 



form : p. 91. 

 A'. Fossilized branch of same Chara, natural size. 

 /. Fossilized stem of ditto, spirally striated. The striae wind round in a contrary 



direction to those of the pericarpium. 

 m. Ditto magnified, showing it to be composed of a large tube surrounded by 



smaller tubes : p. 91. 



Fig. 2. a. Pericarpium or seed-vessel of recent Chara hispida, from the Bakie Loch : 

 of the natural size : see p. 92. 

 b. Integument of ditto, magnified 20 diameters, of the same species as that fossil- 

 ized in Bakie (represented in b. Fig. 1.), but smaller, as being less ripe. Each of 

 the five spiral valves turn rather more than twice round the circumference ; the 

 whole together making between 10 and 11 rings : p. 91. 



