94 Descriptions of New, or Little Known, Polyzoa. 



from different parts of one cylinder. They are all directed 

 upwards, and are frequently nearly parallel to that from 

 which the} 7 have risen. The cylinders are very much 

 thicker, and the situation and form of the mouths of the 

 cells are different. Moreover, the opercula and avicularia 

 differ considerably, as will be seen by a reference to the 

 figures. The lower part of the operculum is clouded with 

 a close mottling, which is wanting in that of C. fistulosa,, 

 which is also smaller ; and the avicularium is much wider, 

 shallower, and sharper at the extremities. 



As the opercula of the different species of Cellaria afford 

 a valuable and easily applicable mode of discrimination, 

 which has not hitherto been made use of, I have figured 

 those of all with which I am acquainted, including the 

 European C. fistulosa and sinuosa. In every case it is 

 characteristic; and where there is the closest resemblance 

 (C. fistulosa and hirsuta and G. gracilis and tenuirostris) 

 the avicularia are totally distinct. 



Family, Tubuliporim:. 



Tubulvpora concinna, n. sp. Plate I., fig. 10. 



Zoarium nearly discoid, with a thin, smooth, or concen- 

 trically wrinkled lamina. Cells arranged in radiating, 

 linear series, partially immersed in greater part of their 

 extent, distinct and separated from each other, slightly 

 contracted towards the orifice, which is produced into a long 

 peristome ; surface of cells with numerous white, prominent 

 puncta, and frequently slightly rugose ; intervening surface 

 punctate in the same manner, or with white-bordered pores. 

 Ovicells long, narrow inflations transverse to the rows of 

 cells. 



Port Phillip Heads, on shell and algse ; found also by 

 Mr. J. B. Wilson. 



This is a well-marked species, and shows the transition 

 to Diastopora. The zoarium is discoid, but with the origin 

 of the rows of cells in some specimens eccentric. One speci- 

 men shows a nabelliforrn arrangement, so that no doubt 

 this is the primary form. The cells are arranged in more or 

 less radiating series, separated from each other by the 

 general surface of the zoarium. They are in great part sub- 

 immersed, but mostly free and turned forwards at the 

 extremities,, especially in the cells remote from the margin. 



