ENNEAGONOIDES. 65 



the cavity is prolonged beyond the general level of the truncated flat part of the lower face, 

 and the lateral walls send down thin processes, deeply notched on their free edges, to meet 

 this prolongation. 



Length of the hydrophyllium . . • jth inch 



Breadth „ „ . . • „ 



Length of the gonocalyx . . . • „ 



AmpJnroa angulata was only taken once, in Torres Straits, and I am strongly inclined to 

 believe that it may be nothing but a younger form of the last species. 



Genus ENNEA.G0N01DES (nov. gen.) 



Biphyozooids derived from (?). 



Hydrophyllium having the general form of a cube with produced angles, but a pointed 

 process is developed from one sohd edge, so that this and the adjacent face are pentagonal, 

 and the body exhibits altogether nine points. The chamber for the polypite is conical. 

 The phyllocyst is simple and oval. 



Enneagonoides Quoyi. pi. IV, fig. 6. 



Hydrophyllium six-sided, with four quadrangular and two pentagonal faces, and much 

 produced solid angles. One of the faces is inferior, and presents towards one angle the 

 rounded aperture of the cavity for the polypite, which is conical, and is connected above with 

 a small elongated phyllocyst. Supposing the side on which this opening lies to be anterior, 

 then the axis of the cavity and that of the phyllocyst are directed obliquely backwards, upwards, 

 and to the right side. 



The superior, anterior, left lateral, and posterior, faces are square, but the right lateral 

 face is pentagonal. 



The organ would be a simple cuboid, were it not for the development of the triangular 

 process (|3, fig. 6 a, b, c), which converts the two adjacent sides into pentagons. 



I regret to find that I have omitted to note the size of this Diphyozooid, which was 

 taken on the east coast of Austraha in 1849. 



I obtained but one specimen of Enneagonoides Quoyi and it had neither polypite 

 nor reproductive organs. 



I was at first inclined to regard this species as the Enneagonum hyalinum of Quoy and 

 Gaimard {'Annales de Sc. Nat.,' 1827), but they state that the hydrophyllium of their genus 



