TuBULitoiiA. POLYPI. 437 



the cells obliquely quincunx, the openings slightly narrowed, and 

 their margin before with a conical tooth, sometimes accompanied 

 by two smaller ones. European and Indian seas Lam. ii. 166. 



Gen. 47. TUBULIPORA, Lam. Cellepora, Gmel. 

 Mass parasitical or incrusting, with submembranous cells in 

 clusters or series, and in a great part free ; cells elongated, 

 tubular, with the opening orbicular, regular, rarely dentated. 



T. Iransversa, Lam. With tubular cells, disposed in transverse 

 rows., and united at their base ; crust creeping on marine bodies 

 Inhabits Mediterranean sea. Ellis, Coral, pi. 27, No. 3, fig. e, E. 



T. orbiculus, Lam. Subincrusting fuci in an orbicular or convex 

 form ; cells tubular, straight, free, and distinct in their upper 

 portion ; mouths subdentated. Inhabits Mediterranean and In- 

 dian seas. Lam. ii. 163. 



Gen. 48. FLUSTRA. 



Submembranous, flexible, stony, frondescent, or in a thin crust, 

 formed of contiguous cells, disposed in numerous regular 

 rows, either on one or both surfaces ; cells sessile, short, ob- 

 lique, with the opening terminal, irregular, often dentated or 

 ciliated on the margin. 



* Expansions foliaceous, elevated, not incrusting. 



^F.foliacea, Lin. Foliaceous, branching, with deep cut lobes, and 

 cellular on both sides ; lobes wedge-shaped, the apex rounded ; 

 margin of the cells with four or live short spines. Inhabits seas 

 of Europe. Ellis, Coral, pi. 29, No. 2, fig. a, A, B, C, E. 



F. carbasea, Lam. Foliaceous, dichotomous, cespitose ; the lobes 

 linear, wedge-shaped, obtuse ; cells disposed in one stratum, ob- 

 long-oval, with the openings small. Inhabits coasts of Scotland. 

 Ellis, Zooph. pi. 3, fig. 6, 7. Plate 8, Jig. 13. 



** Expansions incrusting, or enveloping, rarely free. 



F. telacea, Lam. Incrusting ulvse and large-leaved fuci, in the 

 form of a thin web, resembling a fine net-work, with oblong 

 quadrangular meshes ; mouth of the cells subnaked. Inhabits 

 European seas. Lam. ii. 158. 



F. dentata, Lam. Incrusting, sometimes subfrondescent, shining, 

 and stony ; mouth of the cells elliptic, multidentate. Seas of 

 Europe, on the stems of fuci Ellis, Coral, pi. 29, fig. D, D, I. 

 Fossil species of this genus have been found on remains of shells and Crustacea. 



SECTION VI. 



Polypiferous masses of one substance only, with slender fistu- 

 lous, membranous, or horny stems, flexible and branching, 

 containing polypi in their interior. 



The polypi of this section form elongated, flexible, slender, branched, and trans- 

 parent stems, resembling delicate plants. The stems and branches are fistulous, inor- 

 ganic, of a horny substance, and contain the polypi, which are attached to the com- 

 mon body by their posterior extremity. The cells are terminal or lateral, project- 



