440 POLYPI. VAGINATI. 



The Plumulariae are known at first sight by their branches being disposed in ge- 

 neral like the webs of a feather. 



P. myriophyllum, Lam. Stem slightly divided, pinnated j pinnulae 

 alternate, long, curved, crowded ; cells truncated, supported at 

 the base by an obsolete spinous process. Inhabits European seas 

 Ellis, Cor. pi. 8. 



P. setacea, Lam. Simple, pinnated ; pinnae alternate, subincurv- 

 ed ; cells minute, distant, denticulated. 3 inches long. Inha- 

 bits European seas. Ellis, Zooph. 47* 



P. cristata, Lam. (S. pluma, Lin.) Loosely branched, subdicho- 

 tomous ; pinnae of the branches straight ; cells companulate, ses- 

 sile ; vesicles crested. Inhabits European seas. Ellis, Cor. pi. 7, 

 No. 12, fig. b, B. 



Gen. 58. ANTENNULARIA, Lam. Sertularia^ Ellis. 

 Horny, with fistulous stems, simple or branched, articulated, and 

 furnished with verticillate, slender ramuli ; cells distant. 



A. ramosa, Lam. (S. aniennina, Ellis.) Stem erect, simple, or al- 

 ternately branched ; branches of the whorls slender, incurved ; 

 cells distant, unequal, slightly campanulate ; vesicles pedunculat- 

 ed, ovate. Inhabits European seas, on oyster beds Ellis, Cor. 

 pi. 9, No. 14, b. 



Gen. 59. SERTULARIA, Lin. 



Horny, with slender fistulous stems, simple or branched, and 

 furnished, as well as the branches, with separate and lateral 

 dentiform cells ; cells projecting, sessile, or subpediculated, 

 scattered, or disposed in two opposite rows ; vesicles larger 

 than the cells. 



The polypi of this genus appear in the form of small plants deprived of leaves, or 

 of which the leaves are extremely small. The stems are in general transparent and 

 very slender, and the greater portion finely branched. They appear as if dentated 

 longitudinally by the projecting, separate, and lateral cells. These cells are small, 

 numerous, sometimes opposite and sometimes alternate. They vary in their form 

 according to the species. The Sertulariae are found adhering to rocks, fuel, shells, 

 and other marine bodies. 



* Cells subpedicellate. 



S. laxa, Lam. Alternately branched ; branches simple ; cells al- 

 ternate, remote, pedicellate Lam. ii. 116. 



Cells sessile. 



S. abietina, Lin. Alternately and bifariously pinnated ; cells sub- 

 cylindrical ; vesicles oval, with a narrow base, and a contracted 

 tubular summit. About a foot long. Inhabits European seas. B. 

 Ellis, Cor. pi. 1, No. 2, fig. b, B. 



S. cupressina, Lin. Branches compound, elongated ; ramuli alter- 

 nately divided ; cells subcylindrical, obliquely truncated ; vesi- 

 cles subovate, with a subtubular orifice. Inhabits European seas. 

 B. Ellis, Cor. pi. 3, No. 5, fig. a, A. Plate 8, fig. 12. 



IS. pumila, Lin. Branches irregular, numerous, and bifarous ; cells 



