84 Mr. G. U. Vine on Species of 



other features which it may be well for the reader to refer to^ 

 the stellate cluster being a continuation of the fibre at 3*. In 

 following the above remarks it will be easily understood that 

 I attach very great importance to the method of formation and 

 the character of the tongue-like vesicles which form the radii 

 of this anomalous species, A. radiciforme. Sometimes after 

 single vesicles are formed, at other times after a combination 

 of vesicles, the organic matter of the thread or fibre undergoes 

 other changes, to which reference has not been made. A group 

 of vesicles combined as in fig. III. 3*, some of the cells, and 

 occasionally the whole of them, will contract towards the 

 centre or separate from the nucleus, forming club-like cells. 

 In nearly all the instances where I have seen this mode of con- 

 traction the cells have a very delicate covering of calcareous 

 matter, and are foraminated either in a single line along the 

 centre or indifferently over the whole surface ; the latter^ 

 however, is a very rare occurrence. I have given figures of 

 the club-like cells (fig. III. 4 a. Ah), showing the direction and 

 positions of the foraminated surfaces ; but in fig. III. 4 I have 

 shown the basal attachment of one of the fibres, which shows 

 that the under surface was more densely foraminated than 

 the upper. The irregular fibre shown in fig. III. 6, though 

 not strictly speaking a portion of a stellate cluster, is likewise 

 foraminated. 



In the ' Journal of the Cincinnati Society of Natural 

 History; 1879, voh ii. pi. vii. figs. 24 and 24 a, Mr. E. O. 

 Ulrich describes and figures a very peculiar fossil adherent 

 to the exterior coat of StrepteJasma cornieulum. For the 

 species a new genus is founded — BJiopaJonarlaj from rhopalony 

 a club — which Mr. Ulrich places in the family Crisiidai ; and 

 he says that " the genus is related to Hi'p'pothoa, but in the 

 form and arrangement of the cells they differ widely." There 

 is not, however, any relationship to Hi'ppotlioa in the species 

 described ; but as the cells are somewhat club-shaped, it may 

 be well to accept the genus if more fully defined. 



In the species, li. venosa, Ulr., the " cells are uniserial^ 

 long, acutely elliptical, and joined together at their contracted 

 ends. . . . Cell-mouths not clearly determined, hut appear to 

 he situated near (he oniddle of the celV f. In my own speci- 

 men of this species I cannot detect any cell-mouths, but the 

 other characters are well defined by the author. 



In the Ludlow rocks and also in the Wenlock shales there 

 are several fossils that might have been conveniently placed 

 in this genus if my specimens did not throw soiije little light 



t Italics mine. 



