EAELY PALEOZOIC BEYOZOA OF THE BALTIC PROVINCES. 



219 



Bpaces between the rays elevated and occupied by two or three short rows or clusters 

 of closely approximated apertures; mesopores aggregated into maculae, internally 

 with gradually crowding diaphragms. 



Genotype. — Ceriopora constellata (Van Cleve) Dana. Upper Ordo- 

 vician of the Ohio Valley. 



CONSTELLARIA VARIA Ulrich. \ 



Text figs. 120-122. 



Constellaria varia Ulrich, Geol. and Nat. Hist. Surv. Minnesota, vol. 3, pt. 1, 

 1893, p. 311, pi. 21, figs. 1-7. 



Several well-preserved specimens of a ramose species of Constellaria 

 from the Jewe limestone (Dl) and Wassalem beds (D3) proved upon 



Fig. 120.— Constellakia vabia. a, fragment of a zoakium, natural size; b, surface of a MATxmE 



SPECIMEN, X9; C, TANGENTIAL SECTION, XIS; d, SMALL PORTION OF THE SAME, X50, "WITH TWO MURAL 

 TUBULi; e, VERTICAL SECTION OF AVERAGE EXAMPLE, X18. NeMATOPORA BED OF TKENTON, NEAR 



Cannon Falls, Minnesota. (After Ulrich.) 



careful comparison with the American form to be identical with the 

 well-marked Constellaria varia Ulrich from the Lower Trenton strata 

 of Minnesota and other States. Figure 120 represents the external 

 and internal features of the American type and will serve equally 

 well for the identification of the Russian specimens. The internal 

 characters of a well-developed specimen from Uxnorm are shown in 

 figure 121. Comparing this with the corresponding figures of the 

 American form, the tangential sections are seen to be practically 

 identical, while the slight difference in the vertical sections is due 

 solely to the greater development of the mature region in the Russian 

 specimens. The figured vertical section passes through a macula, 

 and thus gives the appearance of a greater development of mesopores. 

 Ulrich's description of the species is quoted below. 



Zoarium consisting of one or more irregularly dividing branches arising from a 

 broad basal expansion. Branches usually compressed, generally from 8 to 10 mm. 

 wide, but varying between the extremes of 3 and 15 mm. Maculae large, irregularly 

 92602°— Bull. 77—11 16 



