. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. Structure of Heteropora neozelanica, Buslc. 419 are regularly polygonal and thin-walled. Moreover, in place of large tubes mixed up singly in great numbers with smaller Fig. Thin sections of a typical example of Monticulipara pvlchella, E. & H., from the Wenlock Limestone of Dudley. A. Part of a tangential section, enlarged eighteen times, not passing through one of the groups of larger corallites. B. Part of a longitudinal section, enlarged eighteen times. Both sectio
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. Structure of Heteropora neozelanica, Buslc. 419 are regularly polygonal and thin-walled. Moreover, in place of large tubes mixed up singly in great numbers with smaller Fig. Thin sections of a typical example of Monticulipara pvlchella, E. & H., from the Wenlock Limestone of Dudley. A. Part of a tangential section, enlarged eighteen times, not passing through one of the groups of larger corallites. B. Part of a longitudinal section, enlarged eighteen times. Both sections show that the wall of the tubes has the same structure as is characteristic of Favosites; and the latter exhibits the remote tabulae which intersect the cavities of the tubes. tubes, we have clusters of large corallites (fig. 3, D) inter- spersed at short intervals in a general basis of smaller coral- lites. In the two points just alluded to, M. pulclieTla. simi- larly differs from such a form of MonticuUpora as M. Jamesi. In other respects, however, its general conformation and plan of structure are the same. As regards the internal structure of M. pulcheUa, E. & H. (fig. 5), we find a much greater simplicity than exists in M. Jamesi. Thus in tangential sections (fig. 5, A) the corallites are seen to be regularly polygonal, with moderately but by no means excessively thickened walls, and showing no trace whatever of radiating spines or " ; The structure of the wall, moreover, is entirely different from that of many Mon- ticuliporids, and agrees precisely with what we find to exist in Favosites. That is to say, each tube is provided with its own calcareous investment, which remains permanently dis- tinct. Hence the wall which separates any two contiguous tubes is always composed of two distinct calcareous laminae, separated by a dark and definite boundary-line which is thickened at the points where three or more tubes come into contact. There are no very
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