Knowlton — Problematic Organism from the Devonian. 203 



broad. They have been hollow spheres and the now solid in- 

 terior has probably been infiltrated through the very small ori- 

 fice at one extremity (See fig. 2). The outer wall has been 



moderately thick and when broken away, leaves impressed 

 upon the nucleus, lines indicating the position of the spirals. 

 (See fig. 3). The " shell " breaks away very easily and it is a 

 matter of some difficulty to obtain absolutely perfect specimens 

 from the matrix. I am unable to detect structure in the outer 

 wall. Ten, or perhaps rarely nine, spirals (cells ?) have entered 

 into the composition of the " shell " (sporostegium ?). About 

 eight turns of the spiral are visible in lateral view. 



The figures and description, it will be observed, correspond 

 very closely, at first sight, to the well known " fruits " of the 

 genus Chara, and the probability of their being fruits of this 

 kind is greatly strengthened when it is remembered that more 

 than forty species have been described in a fossil state, and as 

 I am informed by Prof. J. D. Dana, they have actually been 

 referred with little hesitation to the genus Chara by the late 

 Prof. P. B. Meek, who examined material from this same lo- 

 cality many years ago. Prof. Meek writes of them as follows :* 

 " In the same matrix with the above described shell (Tricho- 

 nema tricarinata Meek) I have been surprised to notice nu- 

 merous minute bodies that I can scarcely doubt are really* the 

 fruits of the fresh- water genus Chara. At any rate, they 

 seem to present all the external characters of the same. These 

 little bodies are globose, about 0'05 of an inch in diameter, and 

 each ornamented by nine strongly defined and very regularly 

 disposed spiral ridges, which start on one side around a minute 

 pit, and pass with perfect regularity spirally, so as to converge 

 to an exactly opposite point on the other side, making each 

 about one spiral turn in passing from side to side. If really 

 the seeds of this fresh-water genus of plants, they must have 

 been carried into the sea by streams, and deposited where we 

 now find them, along with numerous marine shells." This de- 

 scription agrees so closely with my own that there can be no 

 doubt that the specimens are the same. 



* Fossils of the Corniferous Group : Geol. Surv. of Ohio, Palaeontology, vol. i, 

 1873, p. 219, Note. 



