438 POLYPI. VAGINATI. 



ing outwards along the stem and branches of the polypiferous growth ; and the com- 

 mon body continues to increase at the superior extremity, while the lower is progres- 

 sively dried up. Lamarck divides the animals of this section into those which have 

 the cells lateral and those in which they are terminal. 



1. Cells lateral. 

 Gen. 49- POLYPHYSA, Lam. 



Polypiferous mass fungoid, with a calcareous crust, and a sim- 

 ple, filiform, fistulous stem, terminated by a cluster of inflat- 

 ed cells ; cells vesicular, unequal, clustered at the top. 



P. Ausiralis, Lam. With numerous, erect, bundled stems ; head 

 unequal, terminal. Inhabits seas of New Holland. Lam. ii. 152. 



Gen. 50. ACETABULUM, Lam. 



Fungoid, with a calcareous crust ; stem filiform, simple, fistu- 

 lous, terminated by an orbicular flattening, hollow in the cen- 

 tre ; head with radiated striae from above downwards, perfo- 

 rated in the margin, and composed of tubes united orbicular- 

 ty- 



A. Mediterranean, Lam. (Tubularia acetabulum, Gmel.) Crust 

 of the margin regular; stems erect. Inhabits Mediterranean 

 sea, on stones, &c Lam. ii. 150. 



Gen. 51. TIBIANA, Lam. 



Fixed, tubular, membranous or horny, slightly incrusted exte- 

 riorly, perforated on the sides, with the openings alternate, 

 large, and slightly projecting. 



T. ramosa. Lam. Tubes membranous, subflexuose, upper branches 

 white ; cells prominent, inflated. Inhabits seas of New Holland. 

 Lam. ii. 149. 



Gen. 52. DIOHOTOMARIA, Lam. 



Polypiferous mass with tubular, subarticulate, dichotomous 

 stems, and a calcareous incrustation ; cells of the polypi not 

 apparent. 



* Tubular, subarticulated. 



*D.fragilis, Lam. Branching, dichotomous, in tufts, white or whit- 

 ish green ; joints cylindrical, the apex of the last subcompressed. 

 Inhabits American seas Lam. ii. 145. 



D. obtusata, Lam. (Corallina, Ellis.) Branching, corymbose, di- 

 chotomous, jointed ; joints oblong-ovate, subvesiculose, compres- 

 ed when dry. Inhabits coasts of the Bahama Islands. Ellis, 

 Zooph. pi. 22, fig. 2. 



** Not articulated. 

 D.fruticulosa, Lam. (Corallina, Ellis.) Branching, corymbose; 



branches round, rigid, the last short and subacute. Inhabits 



American seas Ellis, Zooph. pi. 22, fig. 5. 



The inarticulated species have been deemed by some botanists to belong to the ve- 

 getable kingdom, and have been named Fucut lichenoides. 



