362 APPENDIX. 



there is a spine^ usually of diminutive size^ on one side and 

 a very large avicularium on the other, and sometimes (but 

 rarelv) an a\icularium of more moderate size on both sides. 

 But the character of the species by which it is more par- 

 ticularly distinguished consists in the presence on a great 

 many cells, in one part or other of the polyzoary, of the 

 two large and strong spines projecting backwards. Tliis 

 retrocession of the spines is alone a sufficient character to 

 distinguish the present species from the South African 

 form above alluded to (C taurina, B.) And the length 

 and lateral position of the ^dtt£e would distinguish the 

 unarmed cells fi'om those of C. elegans. 



12. C umhonata, n. sp. 



Cells more or less pyriform, alate, narrow below, bulg- 

 ing or ventricose upwards. A^dcularia large and strong. 

 Vittse strap-shaped, anterior, extending from the level of 

 the mouth to the bottom of the cell, with elevated acumi- 

 nate papillae or short spines. A broad compressed project- 

 ing process on the middle of the back. 



Hab. — Bass Strait, 45 fathoms. 



The cells in this species are small, inflated or ventricose, 

 and as it w^ere sub -globular above, becoming much at- 

 tenuated below — but the cavity of the cell does not appear 

 to extend into this contracted portion, in which is con- 

 tained the connecting tube strengthened by calcareous 

 matter — the inferior continuation of the lateral alse, which 

 descend from the base of the a\icularium. Owing to the 

 large size of the avicularia, the upper part of the cell is 

 much widened, and the whole acquii'es somewhat of a 

 triangular form, and has a peculiar rugose aspect, derived, 

 in part also, from the large size and elevation of the 

 acuminated papillse, not only of the \dtt8e but on the 

 surface of the cell itself. The central umbo or crest pos- 

 teriorly is a marked feature. 



