BRYOZOA 5g 



zoœcia on ail four surfaces, with very large open pores or pits. On the anterior and dorsal 



surfaces there are two longitudinal rows of alternate zoœcia while at the sides there is one 



row. Spécimens from Cape Horn hâve the zoarium round. 



On one or both sides of the aperture there is a raised avicularium, with an obtuse 



triangular mandible, and at the base of the avicularium a projection forms a kind of denticle, 



contracting the peristome, and giving it the appearance of a Schizoporel- 

 lidan aperture. Where there is only one avicularium the peristomial aper- 

 ture is unsymmetrical, as there is no denticle on the one side ; and in the 

 few cases, where there is no avicularium, both denticles are wanting. 



Larger pièces of this species were found in the spirit material from 

 the Cape Horn Expédition, Dredge 4. Lat. 5o° 25' S.- Long. 67 36' W. ; 

 140 mètres; -\-5.j Centigrade, and from the zoarial growth it was at first 

 taken for C. fovcolata nov. In this spécimen, from Cape Horn, che zoarium 

 is cylindrical, and is attachée! by chitinous radicles. The older zoœcia 



Fig. 2. — Ceïïarinella dulia hâve large pores over the surface, while in the younger ones they are more 

 nov. From Cape Horn, p ronouncec l round the borders ; and the slightly raised ovicells hâve radial 



lat. 5o°52'S.-lonR. 67°36' .. . . . 



w sht-hke pores, indicating îts limits. 



B, mandibles. There is a second spécimen from 177 Cape Horn Expédition, between 



C, colonv, natural size. l'île Navarin and l'île Hoste, 270 mètres, +7.7 Centigrade. Some spéci- 

 mens in the British Muséum, collected by Darwin from Tierra ciel Fuego, and two others 

 from the Straits of Magellan are this species, but the région round the aperture is striated 

 or finely lined, and there are nearly always two avicularia. 



Calcareous sections of the Cape Horn spécimen, from the Paris Muséum, are identical 

 with those of C. foveolata nov. (PI. Y, fig. 2/). 



Habitat. — Off Patagonia, Lat. 5o° 52' S.- Long. 67 36' W. ; 140 met. ; +5.7 C. ; 

 between the islands Navarin and Hoste 270 met.; +7.7 Cent.; Tierra del Fuego; Straits 

 of Magellan. 



Exp. Antarct. Belge. 



Probably from 623, Tangles VIII. Lat. 70 00' S.- Long. 80048' W. 



Bifaxaria denticulata Busk 



[PI. VIII, figs. 14a, b 



Bifaxaria denticulata Busk, Zool. Chall. Exp., vol. X, pt. XXX, p 82, pi. XXIV, fig. 3 ; Waters, Zool. 

 Chall. Exp., Supp. Report, vol. XXXI, pt. LXXIX, p. i5, pi. II, fig. 3i. 



As the material is limited to four small spécimens, but few préparations hâve been 

 made. In those from 563 there were no polypides, while in that from 3og no ova or embryos 

 were seen, but about 20 tentacles can be counted. 



In the Challenger spécimens there are two kinds of mandibles, which were rather a 

 puzzle, but the explanation is, that there is an internai as well as external avicularium, 

 and the mandible of this last is. wider (fig. 14a), and has the lucida near to the distal end, 

 whereas in the internai one the lucida is low down. An internai avicularium has already 

 been alluded to in Systenopora contracta nov. 



There is a long tubular connection from the distal end of one zoœcium to the proximal 



