GENUS BEATRICEA. 89 



appearances very similar to that of corresponding sections in an ordinary Stroma- 

 toporoid, sncli as any species of Glathrodictyon. Wo sec, namely, a number of 

 close-set, rounded or oval, granular masses, which represent the ends of the trans- 

 versely-divided radial pillars. These are also highly granular, and they are some- 

 times unquestionably hollow, though at other times they appear to be solid. The 

 section further shows curved tracts of dark granular matter, formed by the close 

 apposition oftheout ends of the pillars, and representing the points where the 

 plane of the section corresponds with the plane of one of the undulating concen- 

 tric lamina). 



Lastly, the surface of this remarkable specimen (Plato VIII, fig. 8) exhibits 

 innumerable small rounded apertures, of which some are larger than the others, and 

 are arranged in irregular longitudinal lines, which have seemingly a tendency to 

 assume a spiral direction. The larger openings are, almost certainly, the apertures 

 of the hollow radial pillars, and possibly all are of this nature. I cannot be sine 

 however, that these openings are not the result of the removal of the outermost 

 layer of the skeleton. No traces of similar openings can be detected on the surface 

 of most specimens of the same species (B. nodulosa, Bill.), though their absence 

 may only be due to their bad state of preservation. 



It need only be added that though the other species of Beatricea described by 

 Billings, viz. B. undulata, is distinguished from B. nodulosa by its external form, 

 its general structure is precisely the same. I have not, however, succeeded in 

 recognising definite radial pillars in B. undulata, though I do not doubt they 

 would be found were a sufficiently large series of specimens examined by means of 

 thin sections. 



Upon the whole, the balance of evidence seems to me to be in favour of 

 regarding the genus Beatricea as an abnormal type of the Stromatoporoids. I do 

 not recognise any Foraminif eral affinities in it ; and there are various points in its 

 structure, as above described, which seem quite incompatible with its being a 

 Cystiphylloid Coral. On the other hand, it presents many of the features of the 

 Stromatoporoids. This is especially the case as regards its possession of " radial 

 pillars," and when these structures are combined with vesicles, the appearances 

 presented are hardly distinguishable from what is observable in sections of Labechia. 

 Moreover, one of its most abnormal features, namely, the possession of an axial 

 tabulate tube, finds a parallel in the genera Idiostroma, Stachyodes, and Amphipora. 

 I was, indeed, at first disposed to place it in the family Idiostromidce, on the ground 

 of this peculiarity alone ; but the general structure of its tissues is such that, if it be 

 regarded as one of the Stromatoporoids, it would seem to find its most natural 

 place in the neighbourhood of the genera Labechia and Rosenella. The genus 

 Beatricea, in fact, occupies with regard to Labechia the same place that the genus 

 Idiostroma does to Stromatopora. It may, however, be a question, whether, in view 



