2. CRISIA. 7 



One peculiarity of tlie species appears to be the frequency with 

 ■which the continuation of the axis or the terminal internode of a 

 branch is aborted and assumes the form of a hollow conical process 

 (vide fig. 11). The same thing, however, may occasionally be 

 noticed in other species. 



10. Crista holdsworthii, sp. n. (Plate YI.b. fig. 2.) 



Cells 9-11 in each internode, connate throughout, with a short, 

 tubular, cylindrical jwolongation which projects directly forwards ; 

 walls very delicate, sparsely punctured ; branches arising usually 

 from the third, sometimes towards the base of the zoarium, from the 

 second cell. Ovicell ? 



Hub. Pearl-oyster Bank, Ceylon {Holdsworth). 



Growth very slender and delicate. 



11. Crista conferta, sp. n. (Plate VI. a. fig. 5.) 



Cells 13-21 in each internode, nearly the upper half free, cylin- 

 drical, curved forwards ; aperture orbicular or subcUiptical, of same 

 diameter as the tube ; branches one to four from each internode, 

 not opposite ; ovicell closely adnate, median or axillary, (usually) 

 truncate. 



Hab. Cii])c-YeTiMands (E.M.S. ' Herald'). 



A very distinct and well-marked species. It grows in dense tufts ; 

 and the numerous branches arising from each internode are very 

 characteristic. That the curved free portion of the cell is not, as is 

 frequently the case, a mere production of the peristome, is proved 

 by its walls presenting the same puncturation as is seen on the rest 

 of the cell. 



12. Crista tubulosa, n. sp. (Plate VI. a. figs. 3, 4.) 



Zoarium forming dense tufts ; usually two opposite branches 

 from each internode ; 7-9 cells in each internode, long, much pro- 

 duced, ascending slightly, curved forwards ; mouth expanded, orbi- 

 cular; oooecium pyriform, closely adnate, usually placed between 

 the branches. Joints white or light-coloured. 



Hab. Cape-Verd Islands {H.3I.S. ' Herald '). 



The rather close tufted growth of this species may at first sight 

 lead to its being confounded with the preceding ; they are, however, 

 perfectly distinct. 



Other recent forms noticed by Authors. 



13. Crista sertulartotdes, D'Orb. 1851. 

 Proboscina sertularioides, Aud. 1826 ; Savig?}. Egypt, pi. 6. fig. 6. 



Hah. Red Sea? 



May be C.fistulosa, Heller. 



