DESCRIPTIONS OF THE SPECIES. 



CRYPTO a^]M:s. 



ALOAE. 



Cfl ACETABULARIJE (P) 



CONOSTICHUS LesqiTereux, 1876. 



Seventh Rept. Geol. Surv. Indiana, 1875. p. 142. 



Stipe cylindrical, continuous; frond enlarging from the base upward 

 in the shape of a plate or of a cup, or increasing b}^ successive superimposed 

 layers or concentric laminge ; top cup-shaped, concave. 



The above diagnosis, given by Professor Lesquereux in the Coal 

 Flora,^ while differing greatly from the original, published in 1876, is sub- 

 stantially the same as that contained in the last memoir- in which this 

 group of organisms was treated by that distinguished author. So far as I 

 know, no other writer has discussed the nature or affinities of the fossils in 

 the- genus. "When the genus was first established no further suggestion was 

 offered as to its systematic relation than its inclusion in the title "Fossil 

 marine plants." In the Coal Flora, however, Lesquereux remarks that 

 "these organized bodies, whose reference to plants is questionable, have in 

 their mode of growth a relation to some marine Algse of our time, the 

 Acetabular icB, which bear, on a continuous stipe, successive umbrella-shaped 

 fronds, the lower rendered solid by incrustation of calcareous matter." The 

 fossils, whose substance appears to have been equally dense throughout, 

 are further compared with Zonaria. Comparison is made with certain 

 sponges, such as Capellia rugosa Goldf , Camerospongiafungiformis Groldf., and 



' Vol. i., 1880, p. 14. 



2 Principles of Paleozoic Botany: Thirteenth Rept. Geol. Surv. Inii., 1883, pt. 2, p. 34. 



