Zoology.'\ NATURAL HISTORY OF VICTORIA. [Polyzoa. 



Description. — A pair of cells in an internode, with three at a bifurcation ; 

 connecting- tubes short and double ; aperture nearly circular, largely filled in by a 

 tubercular calcareous plate, usually broader below and leaving- a subtrianguiar 

 opening- ; 3 or 4 long- slender spines articulated to the upper and outer marg-in of 

 the aperture. Avicularium, when present, with the mandible opposite the calcareous 

 plate filling- in the lower part of the aperture. Ovicell dpe])ly immersed. 



Reference. — Gray, DiefFenbach, New Zealand, ii. 293; Busk, Brit. Mus. Cat. 

 Mar. Pol., p. 28, pi. xl. 



Queenscliff and other places. 



Forms small curling tufts attached to algae and polyzoa. The 

 avicularia are frequently wanting in all the cells of a specimen. 

 When present they are small and situated so that the mandible opens 

 opposite the lower edge of the aperture. When ovicells are present 

 there are three cells in an internode, the ovicell being globular and 

 deeply immersed in the upper cell, which is situated to one side and 

 not mesially, as in the tricellular internode of a bifurcation. In 

 this species, as in M. cervicornis, in addition to the usual bifurcating 

 branches, one occasionally springs from the front of a cell. 



Explanation of Figures. 



Plate 58. — Fig. 2, specimen, natural size. Fig. 2a, portion, magnified. Fig. 2A, two inter- 

 nodes, more highly magnified ; a deeply immersed ovicell is shown in the ujtper cell of the 

 upper internode, and the lateral avicularium is seen in the left-hand cell of the lower. 



I follow Wyville Thomson, whose generic character I have 

 given, in uniting Em7na with Menipea as I cannot see that there 

 is any sufficient distinction between the two genera. Emma is 

 distinguished from Menipea by the aperture being contracted by 

 a more or less granular plate, and by the lateral avicularia being 

 situated below the level of the opening. All the species here 

 described certainly lielong to the same genus. In M. cijathus the 

 granular plate is replaced by a slightly thickened rim, occasionally 

 wider at the lower part ; and the situation of the avicularium varies 

 from opening opposite the upper third, as in M. Baskii^ to opposite 

 the lower edge of the aperture, as in M. crystallina. 



• [32] 



