STRUCTURE OP POLYPIDOM AND POLYPES. 187 



allied to Pennatula, but of a much more slender form, 

 resembling a rod, whence its name. It is several inches 

 long and quite straight, traversed by a cylindrical calca- 

 reous stem or column, coated with a transparent flesh. 

 Through nearly its whole length this rod-like body is fur- 

 nished with short fin-like lobes of a crescent shape, which 

 approach in pairs, but are not strictly opposite ; they 

 are about the eighth of an inch asunder, and are fur- 

 nished along the margin with a row of urn-shaped polype- 

 cells. These lobes have the power of contracting, so as 

 to lie closely imbricated one on another ; and of expand- 

 ing to an angle of about 30, so as to leave open spaces 

 between. They are of a pale orange-fawn colour, grace- 

 fully curved backwards, and each contains about eight 

 polype-cells. The Polypes are objects of great beauty, 

 and their form may be very well seen even after death; 

 for, though capable of retractation within the cell, the 

 tentacula have no contractile power, and may be made 

 to expand in their full extension by merely pressing 

 upon the cell. The Polype thus displayed is an eight- 

 rayed star, the rays curved backwards, channelled, and 

 elegantly pectinated along each margin. In the centre 

 is the mouth with prominent lips. The Virgularia is 

 found chiefly in Scotland and the north of Ireland, and 

 I have taken it recently on the Galway coast in Bur- 

 turbui Bay. The only remaining British Zoophyte of 

 this group, Pavonaria quadrangularis, is exceedingly 

 rare, and has as yet been taken only near Oban, on the 

 West of Scotland. In its form it bears a consider- 

 able resemblance to the Virgularia, but is curved, 

 and of much greater dimensions, the length being 



