ONTCH.OCELLA. 2 1 5 



a blunt upper end; the lower margin is entire and but slightly 

 curved, and has a somewhat raised thin margin; the aperture is 

 large. Front wall small, triangular, depressed ; minutely granular. 

 Raised rim, plain, non-crenulate. 



Avicularia large, vicarious ; long, tapering at each end ; irregu- 

 larly scattered over the zooecium. Apertures obovate. A small, 

 triangular front wall both above and below the aperture. 



Dimensions. Length of a zooacium 1 mm. ; breadth 0*8 mm. 



Distribution. Bathonian Calcaire 4 polypiers : Ranville, 

 Prance. 



Description of Figure. Fig. 22. Part of zoarium, X 17 dia. 

 D. 181. 



Affinities. Lamouroux gave a rather unsatisfactory figure of 

 a Bryozoan, which I feel no doubt is the same species as that 

 which I described in 1894. I had noticed Lamouroux's figure, but 

 overlooked the fact that he had named and described it, as he 

 only did this in a footnote to the explanation of the plates. 

 Lamouroux's figure was so indefinite that Pictet gave a figure 

 of a form, which he referred to this species, but which was really 

 a Diastopora lamellosa. But for the British Museum specimen, 

 I should not have been able to determine the genus, for 

 Lamouroux's figure is not sufficiently precise. 



The closest allies of this species are four from the Cretaceous, 

 which have been described under other generic names. It is 

 unfortunate that there is some doubt about its nearest ally, a 

 Maestrichtien species, described by Hagenow : in his monograph 

 he has given two figures * which he assigns to the species Cellepora 

 (Discopora) koninckiana \ but the structure of the aperture is so 

 different in the two, that I feel bound to assign them to different 

 species : in his first figure the aperture is mucronate and is small ; 

 in the second (fig. 11) the aperture is elliptic, with the longer 

 axis longitudinal, the lower margin is entire, the aperture occupies 

 twice as large an area as in the former, and the avicularia are 

 much larger. I therefore make Hagenow's second figure (fig. 11) 

 into a new species under the name of Onychocella hagenowi. This 

 is the nearest ally of 0. flabelliformis, but it differs in the larger 

 size of both the avicularian and zoo3cial apertures. 



Hagenow. Op. cit. p. 95, pi. xi. figs. 10, 11. 



