the orifice, which is produced into a short cj'liiidrical tube of less 

 diameter than the body of the cell, and projecting forwards nearly 

 at a right angle ; branches arising from first to fifth cell ; ovicell 

 ventricosc, closely adnate. 



Crisia eburneo-denticulata, Sniitt, MS. 



Ci'isia eburnea (var.), Smitt, I. c. p. 142 (description of plate), 

 pi. xvi. figs. !), 10, 11. 



llah. Spitzbergen, 70-90 fathoms. 



The general habit and construction of this form is so different 

 from both 0. eburnea and C. denticulata that there can be little 

 donbt of its specific distinction from those species. In the number 

 of cells in each internode it agrees with C. denticulata, as also in the 

 close aggregation of the cells ; but the peculiar production and con- 

 traction of the terminal portion, and the invariably circular simple 

 aperture, suffice, in my opinion, to show its specific distinction ; 

 whilst from C. eburnea it is distinguished by the number of cells in 

 each internode, the point of origin of the branches, the form of the 

 ovicell, &c. In a very long internode, consisting of 17 cells, a 

 second branch was given oflf ; but usually there appears to be only 

 one. The surface of the cells is very finely sulcate longitudinally. 



7. Crisia acropora, Bk. (Plate V. figs. 3, 4.) 



Cells 9-13 in each internode ; a conical tooth (sometimes bifid) 

 behind the aperture ; cells slightly compressed ; surface closely 

 punctured, brilliant, sometimes porcellaneous ; branches arising from 

 second to fourth cell. Ovicell ? 



The radical tubes are much curled ; and they always arise from 

 the bottom of the lowest cell in the internode, behind. 



Crisia acropora, Bk. Voy. of Rattles, vol. i. p. 351. 



Hab. Bass Strait, 47 fathoms. 



8. Crisia margaritacea, n. sp. (Plate VI. b. fig. 1.) 



Cells 13-21 in each internode, connate throiighout, contracted 

 towards the aperture, which is produced into a short cylindrical 

 tube curved abruptly forwards ; occasionally a small tooth behind 

 the aperture : branches arising fi'om fourth to eighth cell, usually 

 from fifth. 



Crisia denticulata, Bk. Voi/. of Baftlex. vol. i. p. ?>51. 



Hab. Australia (' 7?r/^^/''««rtZ-(',' Voy. of ' Fly, ^ Jules). 



9. Crisia sinclarensis, n. sp. (Plate IV. figs. 7-11.) 



Cells 7-9 in each internode, connate throughout ; aperture or- 

 bicular, with a strong denticle behind it ; surface sparsely and 

 irregularly punctured ; branches arising usually from the second, 

 occasionally from the first cell. 



Hah. Coast of Patagonia {Dr. Sinclair). 



