BRYOZOA 49 



« triangula » group, I now consider that it should be separated as a genus, and will 

 temporarily speak of it as the Gemellipora group of Smitt ('), though I hesitate to use the 

 generic naine, as it seems possible, that as revision progresses, the species first mentioned 

 by Smitt, may hâve to remain under Pasythea, while closely allied to others of the group. 

 The opercula of ail are subtriangular ( 2 ) with two small latéral projections, corresponding with 

 two small latéral teeth in the aperture, the muscular attachment is close to the side of the 

 operculum (PI. VIII, fig. 25), and in this respect entirely differs from the operculum of such 

 species as S. Cecilii Aud., S. Ridleyi MacG., &c. The aperture of the ovicelligerous zoœcia 

 differs in shape from that of the ordinary zoœcia, in most species being wider with a flatter 

 sinus. In this character it is similar to Hippothoa, and they are nearly allied gênera. In the 

 Gemellipora group as restricted, the front of the zoœcium, as at présent known, has large pores 

 and the ovicell is also more or less perforated. The size of the aperture is, within moderate 

 limits, the same throughout the group. 



The species now placed under Gemellipora are G. triangula H., G. lata MacG., G. subim- 

 mersa MacG., G. ambita Waters, G. arrogata Waters, G. venusta Norm., G. scabra Hincks, 

 G. cincta, var. H., G. inconspicua Hincks. As this group is not représentée! in the Antarctic, 

 further discussion is not required. 



The next is the S. Ridleyi group, in which immediately below the aperture there is 

 an avicularian chamber spreading out on both sides. The operculum fits into a wide sinus, 

 and has muscular dots some distance from the edge of the operculum ; and hère again 

 throughout the group the aperture is about the same size, and the oral operculum closes 

 the ovicell (') (PL VIII, fig. 23). The surface of the zoœcium and of the ovicell is usually 

 smooth. 



Jillien based his genus Buffonella on the imperforate front, and said there was only 

 one species known. Perhaps it might be as well to extend Julliex's diagnosis and retain 

 the genus Buffonella. 



The species examinée! are S. Ridleyi MacG., S. simplex d'Orb., S. rimosa Jull., S. mar- 

 supifera B., 5. tumida H., S. levata H., S. laevigata Waters, also 5. Edwardsiana d'Orb. This 

 is a group well représentée! in the southern hémisphère but only known in the northern from 

 one species. 



Hincks when he described the genus Schizoporella did not fix on any species as the 

 type, but mentioned S. sanguinea Norm., and 5. linearis Hass. as belonging to it. Either 

 of thèse can be taken as the type, and in both the muscular attachment is close to the 

 side of the operculum ; the lower edge of the operculum is straight, with a projection in 

 the middle, fitting into the sinus of the aperture (PI. VIII, fig. 22). The front walls of the 

 zoœcia and of the ovicells are perforate. This includes S. linearis Hass., 5. sanguinea Norm., 

 S. auriculata Hass., &c, and is closely allied to the Gemellipora group, but the ovicelligerous 

 zoœcia do not differ from the ordinary zoœcia. This group may ultimately remain 



(1) Floridan Bryozoa, p. 35. 



(2) Cribrilina clithridiata Waters has a similarly shaped aperture with an interior tooth on each side, where 

 the aperture contracts, and it differs so much from other Cribrilina in this particular, that its position is doubtful 

 at présent. 



(3) 5. biaperta Mich. and S. divisopora Waters hâve similar opercula. 



VII R 21 



