EXPLANATION OF PLATES. 



Plate IIL 



Fig. I. — Gigartinites antiguus Brong., sp. 



Fig. 2. — Fucoides slrictus Brong; a. natural size; b. a small portion 

 enlarged, showing dots along each side of a central depression. 

 Fig. 3. — Licrophycus? circinatiis Brong., sp. 



Plate IV 



Fig. I. — Gigartinites reciirvus Brong., sp. 

 Fig. 2.— Gigartijiites furcatus Brong., sp. 



Plate V. 



Fig. I. — Gigartinites fiircatiis Brong., sp. 

 Fig. 2. — Gigartinites diffortnis Brong., sp. 



Fig. 3. — Gigartinites targionii Brong , sp. (This figure also shows 

 a well-defined worm burrow.) 



(All the figures are after Brongniart.) 



