90 Hev. T. Hincks's Contributions towards 



longitudinally ; front of the cell much elevated immediately 

 below the aperture, and on the summit of the elevated portion 

 two massive subtri angular nodules, their apices about meeting 

 in the centre (occasionally uniting so as to form a wall across 

 the cell), lineated transversely; below the rising the cell 

 slopes abruptly to the base. Avicularia infrequent, distri- 

 buted over the zoarium, placed at the" base of a cell, imme- 

 diately under the nodules ; mandible triangular, sloping 

 upwards. Ocecium (?). 



Loc. Australia, incrusting stem of weed (Miss Jelly). 



This species belongs to the same section as the last. 



The cells are arranged with great regularity ; and the ele- 

 vated portions bearing the large nodules form prominent 

 transverse ridges across the zoarium. M. transversa seems 

 to be nearly related to M. Woodsii, Macgillivray * ; but the 

 latter is destitute of the peculiar elevation of the front wall 

 and the nodules. 31. dispar, Macgillivray, is another Aus- 

 tralian species belonging to the same group. 



Siphonopoeella, nov. gen. 

 Der. (ricpwv, a tube, and nopos. 



Gen. char. — Zocecia with raised margins, front depressed, in 

 part membranaceous ; a small calcareous tube with wide 

 mouth placed at one side of the lamina below the aperture, 

 and opening into the cavity of the cell. Zoarium (in the 

 only known species) incrusting. 



We have no clue at present to the function of the curious 

 tubular structure with which each cell is furnished in this 

 form ; but we may infer, I think, from its constancy and 

 definite position, that it bears some not unimportant relation 

 to the economy. It is a very marked structural element, and 

 seems well entitled to stand as the characteristic of a generic 

 group. In the only known species the tube is somewhat 

 horn-shaped, expanded towards the mouth, and attenuated 

 towards the base. I have not been able to ascertain whether 

 or not it comm unicates with the chamber which occupies the 

 lower portion of the cell. 



Siphonojporella nodosa, n. sp. (PL XI. fig. 10.) 



Zocecia subquadrangular, oblong, slightly arched above, 

 prolonged below the area, arranged pretty regularly in longitu- 



* "Description of some new Genera and Species of Australian Polyzoa; 

 to which is added a list of species found in Victoria. By I'. H. Mac- 

 gillivray, A.M., M.E.C.S.," Trans, & Proc. Roy. Soc. Victoria, vol. ix. 

 ( 1868) pt. 2, p. 130. 



