BUGULA TURBINATA. 77 



habit, of an orange-brown colour when recent, but much 

 paler when dried. The cells are somewhat elevated at the 

 upper extremity ; and each of them slightly overlaps the 

 one above it. The number of spines is universally, so far 

 as I have seen, three : two are placed on the outer side of 

 the cell — one of them on the upper angle of the aperture, 

 and the second behind it ; the third rises from the inner 

 and upper angle. The avicularium is the striking feature 

 of the species. It is of very large size, elongated, with a 

 much produced beak, which is slightly and gradually (not 

 abruptly) curved ; the head, as seen from above, has the 

 appearance of being compressed laterally, and altogether 

 wants the full rounded contoui* which we find in the 

 avicularium of the next species. The ovicells are pro- 

 duced in immense numbers ; they are very prominent, 

 owing to the elevation of the cell at the upper extremity, 

 and, as seen in profile, have a very hood-like appearance. 

 The aperture is contracted. The branches are numerous, 

 and set closely together, and wind round the stem in 

 corkscrew fashion. They divdde dichotomously a little 

 above the base into two principal segments ; and these 

 divide and subdivide, the whole assuming a flabellate 

 character. 



BuGULA TURBINATA, Alder. 



Plate X. figs. 5-8. 



Bird's-head Coralline, Ellis, Corall. pi. xxxviii. figs. G-, H. 



Cellularia avicularia, Pall. Elench. 68 ? : Gosse, Devonsh. Coast, 195, 



pi. X. 

 BgGULA TURBINATA, Alder, Quart. Journ. Micr. Sc. v. 174, pi. xvii. figs. 1-4 : 



HincJcs, Der. & Coruw. Cat. 37 (sep.), 



Zoarium orange -coloured when living, forming an as- 



