SPECIES OF nETEEOPOEA. 725 



"Waters's description and excellent figures, they do not quite 

 agree, I Lave thought it might be useful to place on record a 

 short description of the JSTew-Zealand form in the ' Linneau Pro- 

 ceedings.' 



In the absence of more complete acquaintance with Mr. Waters's 

 form, I have provisionally designated the present one 



Heteeopoka -neozelakica, n. sp. ? (PI. XV. figs. 1-4.) 



Zoarium erect, composed of short divergent branches, springing 

 from a short thick stem, and soon dividing once or twice dicho- 

 tomously, and terminating in blunt rounded extremities. The 

 diameter of the primary branches is about "2 inch and of the 

 terminal ones about -1 to -15 inch. The surface presents orifices 

 of two kinds, though scarcely distinguishable in size. The larger 

 ones, in the older parts of the growth, have a slightly raised 

 peristome and are quite circular ; the others (cancelli), disposed 

 more or less regularly round these, generally to the number of 

 7 or 8, are more or less angular, and the border of the opening is 

 never raised. 



In the perfect state the surface, as in most Polyzoa, is covered 

 with a thin chitinous pellicle, by which the cellular openings are 

 more or less closed. In the New-Zealand species this epithecal 

 coat does not seem to become calcified or thickened, as in IT. pel- 

 lictdata, Waters, but always retains a delicate membranaceous 

 character, and it is easily removed by caustic soda. Nor have I 

 been able consequently to perceive the minute openings in 

 the covering of the cancellar orifices described by Mr. Waters. 



In sections the walls of the zooecia and of the intermediate 

 barren tubes or cancelli are perforated, as described and figured 

 by Mr. Waters, by numerous infuadibular pores, by which, as it 

 would seem, facilities exist for the permeation of fluids throughout 

 the entire zoarium. These pores and pore-canals are lined, like 

 the zooecia and cancelli, with a thin animal substance, which is 

 readily dyed by any aniline colour &c., by which, means the pore- 

 canals are rendered beautifully distinct in thin sections. 



The chief points of diff'erence between mine and Mr. Waters's 

 Japanese form would seem to consist : — (1) in the difi'erence of 

 habit — the branches in IT. pelliculata appearing to be longer and 

 more terete and to be occasionally connate, whilst in R. neoze- 

 lanica they are short and not terete, expanding and never joined 

 together ; and (2) in the absence in H. neozelanica of the eal- 



