VII.] CYMOPOLIA. 169 



Eocene specimen bears the closest resemblance to the recent 

 spicule of fig. 33, H, and emphasizes the very close relationship 

 between the fossil forms and the single rare tropical species. 

 2. Acicularia miocenica Reuss. Another Tertiary species 

 has been described under this name by Reuss ^ from the Miocene 

 of the Vienna district, from the Leithakalk of Moravia and 

 elsewhere. It agrees very closely with the recent species A. 

 Schenckii. A section of one of the spicules of this species is 

 shown in fig. 33, E ; the dark patches represent the pockets 

 in the calcareous spicule which were originally occupied by 

 sporangia and spores. 



Gymopolia. Fig. 33, A, B, M and N. 



The genus Gymopolia is at present represented by two 

 species, C. harhata (L.) and 0. viexicana, Ag., living in the 

 Gulf of Mexico and off the Canary Islands. 



Gymopolia and Acetahularia, with several other calcareous 

 algae, are figured by Ellis and other writers as members of the 

 animal kingdom. Ellis speaks of the species of Gymopolia 

 which he figures as the Rosary Bead-Coralline of Jamaica. 



Fig. 33, M, has been drawn from a figure published by Ellis in 

 his Natural History of the Gorallines published in 1755^ The 

 thallus has the form of a repeatedly forked body, of which the 

 branches are divided into cylindrical joints thickly encrusted 

 with carbonate of lime, but constricted and uncalcified at the 

 limits of each segment. A tuft of hairs is given off from the 

 terminal segment of each branch. The axis of each branch of 

 the thallus is occupied by a cylindrical and unseptate cell which 

 gives off crowded whorls of lateral branches. In the lower part 

 of fig. 33, M, the calcareous investment has been removed, and 

 the branches are seen as fine hair-like appendages of the central 

 cell. The branches given off from the constricted portions of 

 the axis are unbranched simple appendages, but the others 

 terminate in bladder-like swellings, each of which bears an apical 

 sporangium. The sporangia are surrounded and enclosed by 

 the swollen tips of four to six branches which spring from the 

 summit of the sporangial branch. Fig. 33, A, represents part 

 1 Reusfl (61) p. 8, figs. 6-8. » Ellis (1765) PI. xxv. 0. 



