78 DUBLIN UNIVERSITY 



Polyzoarium closely adnate, narrow, unbranched, more or less incur- 

 vate, attenuated towards the point of origin j the cells are biserial (ex- 

 cept towards the base of the polyzoary, where they form a single row), 

 and separated by a median line; they bend towards the sides, and pro- 

 ject slightly beyond the polyzoary, the orifices opening out laterally. 



On stones, coast of Antrim, deep water, not uncommon. 



Sub-Order.— CTENOSTOMATA. 



Fam. — Yesiculahiad^j. 



Gen. Farrella. 



I. F. dilatata, n. sp. (Hincks). PL III., Fig. 7. 



Cells tubulous, sessile } thick, of equal size throughout, opaque, spring- 

 ing from one extremity of a fusiform expansion of the fibre, which is closely 

 adherent, and set round with a number of flattened spinous projections. 



In this species the delicate creeping fibre swells out here and there 

 into cell-like expansions, fusiform, adherent, and furnished round the 

 edge with a variable number of flattened spinous processes. The cells 

 spring from the larger end of these swellings. They are stout, sessile, 

 and not contracted at the base, and of a dark horn colour when dried. 

 The clavate and spinous expansions are analogous to the cell-bearing 

 enlargements of the fibre in iEtea. 



On shell, Antrim (Mr. Hyndman). Isle of Man (T. H.). 



In the Dredging Report for 1858 I have recorded this species as 

 Avenella dilatata; but the Avenella of Sir John Daly ell is a very doubt- 

 ful genus, and I prefer, for the present, to refer it to Farrella as defined 

 by Mr. Busk in the " Microscop. Journal," vol. iv., p. 93. 



