Descriptions of Neiv, or Little Known, Polyzoa. 107 



Family Cellulariice. 

 Cauda tenuis, n. sp. Plate IV., fig. 1. 



Zoarium very slender; cells biserial, elongated; a spine 

 on each side above ; margins thick and crenulated ; aperture 

 elliptical, occupying about two-thirds of the front; avicularia 

 on the median tract large, with the mandible opening up- 

 wards ; vibracula with groove extending beyond the cell 

 and encroaching on that of the opposite series ; setse slender, 

 smooth ; radical connecting tubes slender. 



Port Phillip Heads. 



This is closely allied to the common C. arachnoides, from 

 which it is distinguished by its much smaller size, more slender 

 branches, and especially by the vibracular grooves for the 

 lodgment of the setae extending on the surface of the cell on 

 the other series ; while in C. arachnoides they are confined 

 to the cells to which they belong, not reaching quite to their 

 inner edges. 



Maplestouia simplex, u. sp. Plate L, fig. 2. 



Zoarium formed of slender, dichotomously-divided branches, 

 each division rising from the outer angle of a cell, and each 

 internode being unicellular. Cells elongated, expanded 

 above, narrowed below ; margin thickened and inflected ; 

 the anterior surface filled in by a thin membrane, with the 

 mouth opening by a flap at the upper extremity. Posterior 

 surface smooth. 



Port Phillip Heads, Mr. J. B. Wilson. 



Forms small tufts, about three-quarters of an inch in 

 height, of slender dichotomously-divided branches. The 

 cells are elongated, wide and square above, tapering below, 

 and each gives rise to another at each upper angle, so that 

 the internodes are unicellular. The joints are annulated. 



Family Salicornariid,e. 

 Tubucellaria cereoides, Ellis and Sol. Plate I., fig. 4. 

 Zoarium consisting of cylindrical branches, each branch 

 articulated by a corneous tube to the side of that from which 

 it springs. Cells indistinct ; mouth circular ; peristome 

 slightly projecting; whole surface punctate. 

 Port Phillip Heads, Mr. J. B. Wilson. 



