Progress in the Study of Daemonelix 9 



though often lobed, as if the plant had thrown out fibrous 

 aggregates in various directions. In thickness «they vary from 

 one centimeter and a half to a half centimeter, the averagfe 

 thickness being about one centimeter. The bottoms and tops 

 of these lie in nearly horizontal planes, just as if conforming 

 to the bed of the Pliocene lake on which they grew. May we 

 not conceive of this ancient filamentous alga as growing in a 

 closely tangled colony, fiat on the sand-bars of this lake ? Pos- 

 sibly, as sedimentation went on, the mat of fibres was covered 

 with fine, clean sand, choking out the original stock, perhaps, 

 but allowing certain surviving fibres to grow upward around the 

 edges and center, to form again a similar mat at another stage 

 above the first one. 



Thus would be formed a layer of mat below and above, and 

 a core of sand between, traversed by innumerable fibres. How- 

 ever faulty or fanciful this suggestion may be, it is borne out 

 somewhat by the specimens themselves when seen in section. 

 Thus, we invariably find a conspicuous array of fibres below 

 and above, inclosing a core of sand marked everywhere by 

 scattered fibres. That is, in cross sections we find a periphery 

 of tubules, quite distinct to the eye, surrounding a partly 

 structureless matrix. The writer as well as the reader is not 

 unmindful of the fact that this presupposes very rapid sedimen- 

 tation, such as would all but preclude the probability of plant 

 life. Notwithstanding all this, whether probable or improbable, 

 whether possible or impossible, the plant is there, manifest to 

 the eye, and unmistakable under the glass. 



The Daemonelix cakes are often solitary, but quite as often 

 in pairs or clusters. In the latter case it is interesting to note 

 that they rise one above the other in steps or terraces, the 

 plane of each being coincident with the bedding plane of the 

 surrounding rock. (Plate II., Fig. 11.) 



Possibly, as sedimentation went forward, the original " cake " 

 was covered, with the exception of a vigorous offshoot or so, 

 which grew upAvard, and then under favorable circumstances 



89 



