. Annals of the New York Academy of Sciences. Science. BROWN, RUGOSE CORALS 71 taneously but come in in the same order as the secondary septa. The first one in each counter quadrant appears long in advance of any of the others, and when the others do appear, they follow the same sequence as the second- ary septa. They develop more rapidly in the counter quadrants than in the cardinal, four having appeared in the former when there are only two in the latter. This species agrees with Enterolasma strictum of the lower Devonic beds in that the tertiary septa are united with the secondary septa at
. Annals of the New York Academy of Sciences. Science. BROWN, RUGOSE CORALS 71 taneously but come in in the same order as the secondary septa. The first one in each counter quadrant appears long in advance of any of the others, and when the others do appear, they follow the same sequence as the second- ary septa. They develop more rapidly in the counter quadrants than in the cardinal, four having appeared in the former when there are only two in the latter. This species agrees with Enterolasma strictum of the lower Devonic beds in that the tertiary septa are united with the secondary septa at their inner margins and do not project as free ridges as is the case with the tertiary septa in geologically earlier species. The additional figures are enlarged from the actual sec- tions sawed from individual corallites. Figure 17 (a-e), from a comparatively small individual, shows five sections. In figure 17a there are only two pairs of secondary septa in; the counter quadrants in addition to the four primary septa. The other four sec- tions show the addition of the remaining secondary septa and of the first pair of tertiary septa adjacent to the counter septum, as well as the reduction in prominence of the cardinal sep- tum and the development of the solid pseudocolumella. Figure 18 (a-g) shows similar stages in development and also the presence of tabulae and dissepiments (shown by white in the interseptal spaces). Figure 19 (a-c), from near the base of the calyx of another individual, shows to better ad- vantage the presence of tabula? and dissepiments. These sections show particularly well the reduction of the cardinal septum and development of the cardinal Fig. 16. Stereolasma rectum. (Enlarged.) Heterophrentis prolifica Billings. 1859 Zaphrentis prolifica Billings, Canadian Journal, (new series), vol. IV, p. 121, figs. 22, 23. 1874 Zaphrentis prolifica Nicholson, Rept. on Pal. of Prov. of Ontario, pi. 3, figs. 2, Please note that these images are extract
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