APPENDIX. 39 



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The two lateral teeth are long, acute, and shghtly everted ; 

 the upper third tooth is sharp, but not near as long as the 

 others ; the border of the mouth is as it were excavated 

 below, so that the mouth is as nearly as possible vertical. 

 Contrary to what is the case in S. dweryens, but exactly as 

 is represented in Savigny's figures of the so-called S. 

 disticha (Egypt, pi. 14. fig. 2, 3.); and S. distans (Egypt, 

 pi. 14. fig. 1, 3.) the lateral teeth are sloped or bevelled 

 off fi'om below upwards, and not from above downwards, 

 as in S, dwergens (Mihi.) 



<» 



2. Pasythea, Lamoroux. 

 Cells in distinct sets^ at some distance apart. 



1 . P. hexodon, n. sp. 



Cells in sets of six, — three on each side ; a single axillary 

 cell in each dichotomous division of the polypidom. Ovicell 

 pedunculate ovoid, adnate to the rachis, with a lateral 

 opening. 



Hab. — Off Cumberland Isles, 27 fathoms. 



As this differs in the number of cells in each set, as well 

 as in the form of the cells, and in the form and position of 

 the ovicell, it appears irreconcHeable with Lamouroux's 

 P. quadridentata. According to the figure given of the 

 latter the ovicell is not adnate, and is spirally grooved. 



3. Plumularia, Lamarck. 



a. Angiocarpese — ovicells enclosed in siliquose, costate 

 receptacles. 



1. P. IIuxleyi,n. sp. 



Plumidaria — Huxley, Philos. Trans. Pai't XL, 1849, 

 p. 427. pi. 39. figs. 43 and 45. 



Cells cup- shaped, shallow ; mouth nearly vertical, sub- 

 quadi'angular, margin subcrenate, plicate ; with a small 

 acute central denticle in front, and a wide shallow notch 

 behind. Rostrum twice as long as the cell, arising from 



