APPENDIX. 359 



Colour white, transparent. A fine widely brancliing 

 species, in which the catemilate aspect is more evident to 

 the eye than in almost any other. It is at once recognisa- 

 ble by the rhomboidal scutate form of the cell viewed 

 anteriorly, and, when the back is also viewed, the resem- 

 blance of the two aspects to the back, and breast-plates of 

 a coat of maU, is very striking. The structm-e of the 

 lateral processes is more distinctly to be made out in this 

 species than in any other. Each lateral process consists, 1st, 

 of a deep cuplike cavity above ; 2nd, a middle compartment, 

 the avicularium ; and 3rd, a third loculament below the 

 avicularium, the wide opening of which is covered in by a 

 convex transparent membrane. The bottom of this locul- 

 ament appears to be perforated, and it is to be noticed 

 also that there is a small central perforation in the septum 

 separating it from the cavity of the avicularium. Towards 

 the bottom of the cell, on each side, is a well developed 

 lateral area of exactly the same conformation as the sub- 

 avicularian loculament, and like it covered in by a convex 

 transparent membrane. It might be supposed that these 

 cavities were for the purpose of containing air, in order 

 to render the otherwise heavy branches of the polyzoary 

 buoyant. They, at all events, appear to be perfectly empty. 



7. C. cribraria, n. sp. 



CeUs sub-globular, compressed, more or less alate. 

 Avicularia large, without any superior appendage, and 

 prolonged downwards into elevated lateral alae. Anterior 

 sm'face with numerous small round fenestrse, placed at 

 equal distances apart, and evenly distributed over the sur- 

 face, the circumferential fenestras being larger than the 

 rest. A minute central perforation of a crescentic form, 

 the lower lip projecting, and the upper lip. Ungulate in the 

 middle, falling behind the lower. 



jjab. — Bass Strait? This species also occurs in New 

 Zealand. 



Digitized by Microsoft® 



