BRYOZOA 67 



Smittia tripora sp. nov. 



(PL IV, figs. aa-c) 



There are several spécimens having much in common with the Smittia (Porella) 

 marsupium of MacGillivray, but the zocecia are much larger. There is a distinct dividing 

 ridge, and a row of pores round the border, with a few other pores indicating the com- 

 mencement of a second row. The avicularian chamber is distinct, inflated, in most spécimens, 

 with three or more pores round it, and with large avicularian glands in the chamber (fig. 2c). 

 The operculum is suborbicular, curving inwards on the lower edge, and has a thickened 

 rim running in on each side reminding us of the operculum of S. praestans Hincks, and 

 of the operculum of S. obstructa Waters, which however has a complète ridge across. The 

 ovicell is globular, raised, perforated with numerous pores, and in one case with an indistinct 

 area. 



This is much like the Japanese Porella marsupium var. japonica of Ortmann. 



In the spécimen from N° 618 the surface is very fïnely granulated, and there is a double 

 row of pores round the border. 



Habitat. — Exp. Antarct. Belge. 



N° 618, TanglesVIII. Lat. 7o°oo'S.- Long. 8o°48'W. ; 5oo ? met.; -fo.g C. 



N os 683, ggi, Tangles VIII. Lat. 70 00' S.- Long. 8o° 48' W. ; 5oo ? met.; -fo.g C. 



Smittia praestita sp. nov. 



(PI. VIII, fig. 10a, b) 



Zoarium adnate. Zocecia distinct, hexagonal, raised towards the oral aperture and 

 the peristome carried up in front into a considérable prolongation, the distal portion of the 

 peristome is not raised and has four articulated spines ; at one, or occasionally both sides, 

 high up near to the peristome there is a round avicularium, with a semicircular mandible. 

 Two rows of large pores occur near to the border of the zocecia, the central portion is 

 imperforate, fïnely granular. The ovicell is very small, globose, slightly thrown back, extremely 

 finely granular. About 12 pore chambers round the zoœcium. 



There are only two spécimens and the one from N° 570 is entirely without avicularia, and 

 was at first considered to be 5. praestans Hincks, as sometimes pièces of S. praestans from New 

 Zealand are found with very few avicularia. There are not the areolar ridges as in S. praestans, 

 but also in praestans there are often two rows of pores and the structure of the aperture is 

 quite similar, while the ovicell in the Antarctic species is smaller and is not areolated. 

 With regard to the avicularia found in spécimens N° 5g6, we know, that the round avicularia 

 of Schizoporella anricnlata is sometimes replaced by large spatulate ones, so that a similar 

 change would convert S. praestita into S. praestans. 



Besides being so closely allied to S. praestans Hincks it is also allied to the Arctic form 

 which I hâve called S. Jacksoni Wat. and they belong to the S. coccinea group which occurs 

 in Australia as well as in the northern seas. Levixsen intends to place 5. coccinea in a new 

 genus P eristomella , but as he has not yet diagnosed the genus we cannot discuss it. Smittia 

 praestita is allied to Romancheina Martiali of Julliex, of which spécimens from Cape Horn hâve 



