BRYOZOA FROM S.W. VICTORIA, AUSTRALIA. 



319 



middle of the zooecium ; the band spreads out at the top immedi- 

 ately below the aperture in an oval form, causing an oval depres- 

 sion surrounded by the band. The upper part of the zocecium, 

 comprising the aperture and this oval, is slightly raised ; in the 

 longitudinal depression four or five pores. On the inner side of the 

 zocecium, above the aperture; a small flattened boss ; on the outer side 

 a small triangular avicularium ; a large depression or pore in the 

 middle of the central band. Oral aperture semicircular, with the 

 proximal edge straight ; on the back an irregular oval depression 

 behind each zocecium, with from three to five pores in each of these 

 depressions. 



This is allied to C. solida. Waters (figs. 37, 38) ; but the shape of 

 the aperture is different, besides considerable difference in the 

 structure of the back. At first I thought the large holes in the 

 middle of the centre band were accidental ; but this is really not 

 the case, as in the cells, when there is no hole there, it is replaced 

 by a dark round spot, probably of thinner shell. 



9. Cellaria eistttlosa, L. Plate XIV. figs. 1, 2, 10, 11. 



Cellaria fistulosa has occasioned systematists the greatest difficulty ; 

 and it now possesses a mass of synonyms (for which see Hincks 

 and Heuss), of which many can never be compared. When 

 I examined these and the allied species from this Victorian mate- 

 rial, I at first felt that it would be impossible to separate them, 

 and thought with Reuss that the range of variation was so great 

 that such forms as C. Jistulosa, sinuosa, crassa, marginata, &c. must 

 be included under one specific name. Since my preliminary exami- 

 nation Mi". Hincks's most valuable work on the British marine 

 Polyzoa has appeared, in which he distinguishes three species, 

 Jistulosa, sinuosa, Jolinsoni. I have therefore, with this book before 

 me, again very carefully examined my recent specimens^ first cal- 

 cining considerable portions ; and the conclusions I have come to 

 are : — that the shape of the cell is so variable that it is perfectly 

 useless as a character (this has already been mostly recognized by 

 recent writers, but was the character on which the species were 

 some time ago principally founded) ; then I next found that the 

 bordering rim, which is a character of C. Jolinsoni, Busk, is some- 

 times found on one part of a colony of C. fistulosa, and absent in 

 other parts; next I found the shape of the ovicellular opening 

 equally unsatisfactory (for in most undoubted specimens of fistulosa 

 from Naples it occurs in some cells as a minute orbicular opening, 

 then it is elongate oval, and in other apparently older ovicells a broad 

 semicircular line is formed, which changes to a transversely oval 

 opening, resembling that figured by Mr. Hincks as a character of 

 C. sinuosa). In the same specimen, before any ovicells are formed, 

 the aperture is very near the top of the zocecium ; but afterwards 

 its position is near the centre. Having found the position of the 

 aperture, the shape of the ovarian opening, the shape of the 

 zocecium and of the bordering rim unsatisfactory characters, there 

 only remained the avicularia ; and in all the specimens I have ex- 



