COASTS VISITED BY THE ARCTIC EXPEDITION. 625 



the occasional celluliferous dissepiments, has an opposite tendency, 

 according to the diagnosis of Protoretepora as laid down by Prof, 

 de Koninck. 



Loc. Feilden Isthmus, lat. 82° 43'. 



Genus Ramipora, Toula, 1875. 



New Genus, Salter, Quart. Journ. Geol. Soc. 1860, xvi. p. 441. 

 Ramipora, ¥. Toula, N. Jahrbuch, 1875, p. 230. 



Gen. char. Polyzoarium reticulate, spreading, consisting of a 

 stem or interstice, seldom, if at all, bifurcating, and primary 

 branches, about equal to it in size, arising from the former at 

 regular intervals and on the same level with one another. The 

 primary branches do not show any trace of alternation with one 

 another on opposite sides of the stem, but curve upwards from each 

 side of the latter ; both are divided by an obtuse median keel. The 

 primary branches are united with one another by smaller secondary 

 branches or dissepiments, which likewise arise opposite one another, 

 and either curve upwards, meeting one another in the middle line, or 

 are continued direct from branch to branch without any arching. 

 The fenestrules thus enclosed are either irregularly and obliquely 

 quadrangular, or of a peculiar six-sided or double V-shaped form. 

 Both the stem and the primary and secondary branches are cellu- 

 liferous, but on one aspect of the polyzoarium only, the obverse. All 

 apertures arranged in longitudinal series on both sides the median 

 keels. Reverse of the polyzoarium keeled, but not celluliferous. 



Obs. The genus JRamipora was established by Dr. Toula for a 

 peculiar form of Permo-Carboniferous Polyzoa from Spitzbergen, 

 related to Synocladia, King, Ptylopora (Scouler), M'Coy, and Glau- 

 conome (Groldf.), Lonsdale. It appears to differ from the first of 

 these in the absence of dichotomization of the stem and primary 

 branches, so far as the remains of it are known to us ; in the 

 bilateral symmetry of the latter ; thirdly, in the fact that the cells 

 all open on the same plane on each side the median keels, whereas 

 in Synocladia the stems and branches are divided longitudinally by 

 several carinas, between which the cell-apertures occur. Again, in 

 Ramipora both aspects of the polyzoarium are carinate, but in 

 Synocladia only one. Lastly, in Synocladia the dissepiments all 

 appear to be regularly celluliferous, but in JRamipora this does not 

 appear to hold good to the same extent ; it is, however, a character 

 of lesser importance. In the presence of the principal thick stem 

 and bilaterally symmetrical primary branches we have characters 

 uniting Hamipora and Ptylopora ; but the arrangement of the cells 

 in the two genera is wholly different, and the form of the cross bars 

 or dissepiments, as a rule, distinct. In Glauconome, Lonsdale (= 

 Acanthocladia, King), it will be remembered, there is a stem giving 

 off lateral branches, alternate or subalternate with one another on 

 opposite sides, and trending upwards at various angles, upon which 

 the cells are variously arranged according to the species ; but there 



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