ART. 13 BRYOZOAN FAUNA CANU AND BASSLEE 41 



the large colonies. The colonies are massive, mammillated, more or 

 less expanded, thickened, the largest measuring 3 centimeters in 

 diameter. On the inferior face, they appear to be formed of super- 

 posed lamellae; the section does not confirm this aj)pearance; these 

 pseudolamellae are only foliaceous expansions emitted by the colony 

 probably for the purpose of general consolidation. The same phe- 

 nomenon is noted by MacGillivray, 1895, in the variety nummularia, 

 but the concentric ridges cited by the author do not indicate at all in 

 section true superposed lamellae. 



Busk, 1884, indicated a free, lamellar zoarium. MacGillivray. 1886, 

 observed only small incrusting colonies. Fossil specimens from 

 Australia have small incrusting colonies. The variety nunvullaria is 

 formed of free specimens, more or less globular, but of small dimen- 

 sions. Waters, 1885, indicates colonies of 25 millimeters among the 

 fossils of Aldinga. These variations are habitual in the Cellepores, 

 for the hazards of their precarious life causes them to die at all ages. 



The operculum has very thick margins; the lateral bands are dis- 

 cerned with difficulty. We are not certain of our restoration. Busk, 

 1881, appears to have encountered the small difficulties, for his oper- 

 culum is incomplete. New preparations are very desirable. 



Biology. — The colonies have a brown ectocyst. The ovicell has 

 never been discovered but it has been observed on another species 'of 

 the same group. The sporadic salient tubes also have an unknown 

 zoarial function. When this species is better known it will certainly 

 reveal to us a curious biologic history. 



From inspection of the colonies it is a species both fixed and float- 

 ing. The floating specimens hang directly to algae or to nullipores, 

 themselves attached to floating algae. A substratum so inconstant 

 and mobile can support only free colonies irregularly developed. 

 The lamellar expansions of the inferior face are simply a sort of 

 clamp destined to better fix the colony to its substratum. Only the 

 specimens collected with their substratum have a bathymetric value. 



The small denticles of the apertural poster (lyrule and cardelles) 

 are identical with those of Smittina^ Porella, Mucronella, and 

 Petralia. Their function must be identical, namely, to limit the 

 movement of the operculum and to block it when it is closed. This 

 is an equatorial species. 



Occurrence. — Galapagos Islands, D. 2815. 



Geographic distnhufion. — Pacific: Cape York (8 fathoms). Port 

 Phillip Head and Warnamboul in Australia (Busk, MacGillivray) ; 

 Torres Strait, 15-20 fathoms (Kirkpatrick). 



Geologic distribution. — Miocene of Australia and New Zealand 

 (Waters, MacGillivray). 



Plesiotypes.—Cat. No. 8515, U.S.N.M. 



