There is seemingly also a minute open pore and narrow slits between the cells at the apical end since a specimen treated with dilute hydrochloric acid admits the acid to the interior with the consequent solution of the infiltrated calcite and ebullitions of gas through the neck. The neck, however, is wholly or partly broken off in the majority of specimens. Lengths vary from 0.5 to 0.6 mm., diameters from 0.45 to 0.55 mm.
The presence of an undoubted representative of the Characeae in the Carboniferous is of great interest in connection with the occurrence of minute spirally marked globular organisms, about 1 mm. in diameter, in association with marine fossils in Middle Devonian limestone of Ohio. These were first reported by Meek[1] in 1873 from the falls of the Ohio who assigned them with some doubt to the freshwater genus Chara and was of the opinion that they drifted out to sea. Williamson[2] in 1880 examined similar forms from Kelly's island, Ohio, under the impression that they might be of vegetable origin, but came to the decision that they were foraminiferal and included them in his genus Calcisphaera which had been created to hold somewhat similar globular forms from the Carboniferous of Wales. He named the Ohio forms Calcisphaera robusta. Dawson[3] a few years later, in 1883, pointed out important characters in which the American species from Kelly's island differed from Williamson's description of them. Although Dawson remarks on the superficial resemblance to Chara fruits he agrees with Williamson in referring them to the foraminiferae, but he assigns them to the genus Saccamina as Saccamina eriana. Knowlton[4] in 1889 redescribed the species from the Falls of Ohio and presented at length the various conflicting views held regarding its affinities. The major difficulties against the Characeous affinity are stated to be the presence of nine or ten spiral markings instead of the five in recent and known fossil Chara, the twist of the spirals in a right handed instead of a left handed direction, and finally the abundant uniform distribution of the fossil in a marine formation. In conclusion Knowlton distinguishes the Falls of Ohio form with the name Calcisphaera lemoni. In his review Knowlton failed to recognize the description of the Falls of Ohio species presented by Ulrich[5] three years earlier in 1886. The latter makes no mention of the Chara-like appearance of
- ↑ Meek, F. B., Geol. Surv., Ohio, Palæontology, Vol. I, 1873, p. 219.
- ↑ Williamson, W. C, Phil. Trans. Roy. Soc. Lond., Vol. 171, pt. 2, pp. 520-525.
- ↑ Dawson, J. W., Can. Nat., 2nd ser., Vol. X, 1883, pp. 5-8. Figure 3.
- ↑ Knowlton, F. H. Amer. Jour. Sci. and Arts, Vol. 37, 1889, pp. 202-209, Figures 1-3.
- ↑ Ulrich, E. O., Contributions to American Palæontology, Vol. I, No. 1, Cincinnati, Ohio, 1886.
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