. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 34 J. E. DUERDEN. whether or not the adult arrangement be radiate ; or, stated in another way, the presence of alar fossulae in an adult corallite is a retention of a developmental characteristic. THE CARDINAL OR VENTRAL FOSSULA. Enquiry may now be directed into the nature of the cardinal or ventral-directive fossula. This is the most important of the series, being usually represented in mature calices even when all traces of the alar fossulae have disappeared. Further, its con- stitution is by no means so simple as that of
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 34 J. E. DUERDEN. whether or not the adult arrangement be radiate ; or, stated in another way, the presence of alar fossulae in an adult corallite is a retention of a developmental characteristic. THE CARDINAL OR VENTRAL FOSSULA. Enquiry may now be directed into the nature of the cardinal or ventral-directive fossula. This is the most important of the series, being usually represented in mature calices even when all traces of the alar fossulae have disappeared. Further, its con- stitution is by no means so simple as that of the alar FIG. 7. A third additional metaseptal pair (<•) has appeared within both the mid- dle and ventral chambers, the middle pair developing first. A pair of septa (x) has also appeared, one within each of the dorso-lateral primary chambers, fused with the dorsal directive. In relation to the polyp the septa which appear midway between the principal septa are exosepta, and always constitute the outer, smaller cycle in the mature calice ; the larger septa, constituting the inner larger cycle, include both the protosepta and metasepta, and are entosepta. As represented in Hadrophyllum (Fig. i) the cardinal fossula is associated with two groups of successively shorter septa (b—e), a group being situated on each side of the cardinal or ventral directive septum, and, in addition, the cardinal septum (/) is itself smaller than the other fully developed principal septa. The members of each ventro-lateral group of smaller septa (b—c) are related to one another in the same manner as are the members. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattra
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
