MARINE POLYZOA. 15 



1. CALPIDIUM ORNATUM. PI. XII., XIII. 



Cells triangular-urn-shaped, compressed, very broad above; 

 upper border straight ; mouths 2-3, keyhole-shaped. Five fe- 

 nestrse below each mouth ; numerous branching bands on the 

 back. 



Calpidium ornatum, Busk, Voy. ofRattlesn. i. 364. 1. 1. f. 3, 4, 5. 

 Hab. Bass' Strait, 45 fathoms. 



Cells large, regular, and uniform in size, resembling very closely 

 an antique sculptured urn. Colour dark brown, and the walls so 

 thick as to be nearly opaque. The polyzoary, which appears to 

 attain a height of 4 or 6 inches, is bipinnate (with all the 

 branches on one plane), the branches alternate, and given off with 

 extreme regularity. The ultimate ramules are incurved. The 

 central stem, or series of cells, differs in no repect as regards the 

 size or disposition of the cells composing it, from the branches. 



2. BI-MULTISERIALARIA. Cells disposed in a double or 

 multiple series. 



Fain. 2. SALICORNARIAD^E. 



Cells disposed around an imaginary axis, forming cylindrical 

 branches of a dichotomously divided, erect polyzoary. 



Salicornariana, Gray, Brit. Rad. 131. 



Synopsis of Genera. 



\. Salicornaria. 

 2. Nellia. 



The distinction between the Salicornariadae, as here constituted, 

 and the Farciminariadae is at first sight not very obvious, but 

 further examination will serve to justify their separation. In the 

 Salicornariadae the branches of the polyzoary constitute distinct 

 articulations connected by flexible joints, whilst in the Farcimi- 

 nariadas the polyzoary is continuous throughout. In the Salicor- 

 nariadae moreover the ovicells are deeply immersed, their situation 

 being discernible merely by an alteration in the form of the cells 

 by which they are borne. In the Farciminariadae, on the other 

 hand, the ovicell is external and of the usual cucullate form. 

 The composition of the polyzoary in the Salicornariadae is cal- 

 careous, in the Farciminariadae corneous. Another family, that 

 of the Vinculariadas, to be afterwards described, although agreeing 

 with the Salicornariadae and Farciminariadae in the disposition of 

 the cells around a central imaginary axis, offers sufficient points 

 of difference to justify its distinction from them. 



