120 HYDEOZOIDS AND CORALS. 



polygonal, separated by a common wall. Calyces shallow, 

 with 30 to 40 or more rudimentary septa, which usually appear 

 as vertical striations. 



Horizon and localities. — Lower Carboniferous, Kinder- 

 hook : Sedalia. 



, The precise aflSnities of this group of organisms is not 

 thoroughly understood at present ; so that the synonymy of 

 the genus cannot be given with certainty. Considerable vari- 

 ation is observable both in the size of the corallites and in the 

 number of their septal rudiments. In case of the latter the 

 number is known to be as few as twenty, as stated by Win- 

 chell, and to range as high as forty or more. 



Favosites hemispherica (Troost). 



Plate xiT, fig. 3. 

 Calamopora he77iispherica Troost, 1840: Geol. Tennessee, p. 72. 

 Favosites hemispherica YandeW & Shumard, 1847: Cont. Geol. Kentucky, 



p. 7. 

 Favosites AemisjoAertcaRominger, 1876 : Geol. Sur. Michigan, vol. Ill, pt. ii, 



p. 25, pi. vi, figs. 1-4. 



Corallum rather small in size, usually more or less dis- 

 tinctly globular in shape, sometimes flattened or cylindrical. 

 Corallites unequal in size, polygonal, 2 to 3 millimeters in 

 diameter as a rule, diverging in broad curves from the central 

 axial line ; interior smooth, with simple, flat dissepiments which 

 are rarely compound ; mural pores large, with seldom more 

 than a single row on a side. 



Horizon and localities. — Upper Silurian, Niagara lime- 

 stone; Edgewood (Pike county), St. Louis county. 



Favosites favosa? (Goldfuss). 



Plate xiv, fig. 2. 

 Calamopora favosa Goldfuss, 1826: Germ. Petrif. , p 77. 

 Calamopora favosa Hall, 1852: Pal. N. Y. , vol. IE, p. 125. 

 Favosites favosa Rominger, 1976: Geol. Sur. Michigan, vol. Ill, pt. ii, 

 p. 21, pi. iv, figs. 1-4. 



Corallum often attaining a large size. Corallites polygonal, 

 of tolerably uniform size in the same masses, but ranging froni 

 two to five millimeters in diameter in different individuals ; 

 interior ribbed longitudinally, the intervening space between 



