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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 39. 



section, where a wider angle of divergence results in a more expanded 

 zooecium, contrasting sharply with the narrow, tubular stolon. 



Fig. 12.— Coeynotrypa inflata, illustrating development of unusually long stolons, a and 



6, PORTIONS OF A ZOARIUM, X9 AND X20, INCRUSTING THE BEACHIOPOD RaFINESQUINA SQUAMULA. 



Oedovician, Economy beds of Eden formation, Fort Thomas, Kentucky, c and d, another 

 zoarium, x9 and x20, incrusting a ramose bryozoan. same horizon at west covington 

 Kentucky. 



Comparing the normal examples of C. inflata, for instance, as shown 

 in figure 15, with specimens of the same species possessing elongated 



Fig. 13.— Corynotrypa inflata, illustrating variable length of stolons, a, b, and c, 



THREE portions OF THE SAME ZOARIUM, X9, INCRUSTING THE PEDICLE VALVE OF STROPHOMENA 

 TRENTONEN.SIS. ORDOVICIAN, TRENTON FORMATION, ZyGOSPIRA BEDS, ST. PAUL, MINNESOTA, d, 

 ANOTHER ZOARIUM, X9, WITH UNUSUALLY SHORT STOLONS, BLACK RIVER GROUP, PHYLLOPORINA 

 BED, NEAR CaNNON FALLS, MINNESOTA. €, ZOCECIA, X20, WITH UNUSUALLY LONG STOLONS, GROW- 

 ING UPON A FRAGMENT OF A TRILOBITE. ECONOMY BEDS OF EdEN FORMATION, NEWPORT, KEN- 

 tucky. / and g, a zoarium, x9, and a portion, x20, incrusting rafinesquina alternata. 

 Upper beds of the Eden formation, Cincinnati, Ohio. 



stolons (fig. 12), one might, without a study of this individual varia- 

 tion, refer the two sets to separate species. In the typical forms of 



