173 



judge from the various quoted descriptions and figures the species sterns to be 

 subject to considerable variation, or it may possibly be divided into sevei-al. In 

 the form figured by Waters the ocEcia are very low, and the processes issuing 

 from the free margin of the distal end are sometimes digitately lobed. This may 

 also be the case with the postooecial processes, which may appear as very pro- 

 jecting, flat spines. 



To the genus Aspidostoma I may provisionally refer the following three species 

 from the French cretaceous formation: Eschara Aegon d'Orh. (PI. VI, fig. 3 a), 

 E. Antiopa d'Orb. (PI. VI c, fig. 4 a) and E. Atalantha d'Orh. (PI. VI c, fig. 5 a). 

 In all three of them we find in the proximal part of the aperture a region sur- 

 rounded by protruding margins, similar to that found in A. giganteum, and which 

 may be the frontal wall of a similar polypide-tube. I have however not yet been 

 able to satisfy myself as to whether it sends prolongations to the basal wall. 

 There are other points of similarity, as the partially arched surface of the zooecia, 

 the more or less, projecting distal end, and in E. Aegon and E. Antiopa the pre- 

 sence of postooecial processes. While these in E. Antiopa only take part in the 

 delimitation of the large vestibule, they are in E. Aegon as well as in the just- 

 mentioned form of A. giganteum freely projecting in the shape of flat, almost 

 rib-like processes, which however have here coalesced into a flat, arched band, 

 separated from the free margin of the ooecium by a' transverse slit. In the above- 

 mentioned three species there seems to have been no great number of small 

 rosette-plates, as each distal wall shows one and each lateral wall two trans- 

 versely oval openings, which may originate from as many multiporous rosette- 

 plates. 



I may here add that Canu in two valuable works ^ on tertiary Brgozoa has 

 referred 4 new species to the genus Aspidostoma. 



Crateropora falcata n sp. 



(PI. VI, fig. 1 a). 

 The zooecia, which may attain a length af 1 mm, are generally hexagonally 

 rounded or ligulate, but have sometimes a rather irregular form. With the excep- 

 tion of the proximal margin and a shorter or longer part of the adjoining lateral 

 margins they are surrounded by a raised granular border, which increases in 

 height distally and ends in i curved, strongly protruding distal portion, within 

 the proximal margin of which is seen a low ridge parallel to its free edge of 

 the zooecium. The depressed, very tuberculous cryptocyst is provided with small, 



' 11 a, p, 13—14. lib, p. 278—279. 



