86 BRITISH STROMATOPOROIDS. 



Genus Beatkicea, Billings. 

 (' Geol. Survey of Canada, Report of Progress for 1856,' p. 343, 1S57.) 



Coenosteum in the form of cylindrical or angulated stems, which are nearly 

 straight, are unbranched, and may attain a great size. (Billings states that 

 specimens are sometimes over ten feet in length and more than a foot in diameter.) 

 In the centre of the coenosteurn, running along its whole length, is a large axial 

 tube, crossed by strongly curved calcareous partitions, or tabula?, the remainder of 

 the skeleton being composed principally of lenticular calcareous vesicles, arranged 

 in concentric layers round the axial canal (Plate VIII, figs. 2 and 3). Well-pre- 

 served specimens exhibit radial pillars, resembling those of the Stromatoporoids 

 generally, which intersect the vesicular tissue of the skeleton, and are directed 

 outwards in a radiating manner from the axial tube towards the surface. No 

 zooidal tubes are certainly known to exist. The surface is ridged, or covered with 

 elevated and usually elongated projections or mamelons (Plate VIII, fig. 1). The 

 surface may be apparently imperforate, or may show minute rounded apertures of 

 different sizes (Plate VIII, fig, 8). There is no external calcareous membrane, 

 such as would correspond with the " epitheca" of a Rugose Coral. 



The fossils for which Mr. Billings proposed the name of Beatricea are of a 

 most anomalous character, and have been assigned to very different positions in 

 the animal kingdom by different observers. Most generally they have been 

 regarded as aberrant types of the Rugose Corals, and have been placed in the 

 neighbourhood of the genus Gystiphyllum, a view which is borne out by the broad 

 features of their skeletal structure, but which is rendered untenable by a study of 

 the microscopic characters of the same. They have been referred by Professor 

 Winchell to the Stromatoporoids ; but I have not succeeded in finding any pub- 

 lished account of this view, or of the grounds upon which it was based. The most 

 recent opinion upon the subject of the affinities of Beatricea is that of Professor 

 Hyatt, who formerly referred the genus to the Cephalopoda, but who has been led 

 to the conclusion that it is properly to be placed among the Foraminifera (' Amer. 

 Assoc, for the Adv. of Sci.,' 1884). 



My own studies upon Beatricea have been based in part upon specimens from 

 the Cincinnati Group of Kentucky, and partly upon a number of very interesting 

 examples which my friend Mr. Whiteaves, the accomplished paleontologist to the 

 Geological Survey of Canada, was good enough to send me. These latter were 

 obtained from the Hudson-River formation of Anticosti and of Rabbit Island, Lake 

 Huron. The two species originally described by Mr. Billings, viz. B. nodulosa 

 and B. unclulata, were both represented in the material which I have examined. 



