J\r/r Spi'c'n's (if /b.v.v/V.v frni/i Ol/in. l!)'.) 



rather uiie.\])ectetl feature in its history. The liighest hurizou 

 of its oecurj-ence liitherto recorded, is in the shaly lijiiestone of 

 the Lower llelderherg oroup of Mew YorlK, from which tlie 

 tA'])e of the sjiecies BcceptaciiUies iiifiindibiilifonnis {Cosciniaiit 

 iiifuiuUbiilifonnis, Eaton: Geol. Text-book, :^d Ed., 1833, p. 

 13"-3, fol. 5. tios. G-4. 05) was derived. The lignre and descrip- 

 tion, as given by P]-of. Euton, are both poor, l)nt the specimen 

 is still in the cabinet of the Eensselaer Polytechnic Institute, 

 bearing the original lalxd. and 1 ha^e seen several specimens of 

 the species fnnn the same formation. B. (l((cti/Ioi(/es {Dicfi/O' 

 crinus dactyluides. (-onrad) is also fi'om about the same horizon. 

 Both of these species, however, are in the Silurian, while the 

 present species brings the genus up to the Devonian : so that 

 we now know of its existence from the base of the Lower Silurian 

 to the Lower Devonian. 



KADIATA. 

 Stjla§!rea Anna, ii. ^;p."" 

 Pal. O., Vol. Ill, Plate 2, Figs. 1—5. 

 C'orallum compound, growing in irregular or more or less hemispherical 

 masses of several inches in diameter, which are formed of a' large number 

 of closely aggregated polygonal cell-tubes or i^olyps, of rather small size, 

 divided by intercelltdar walls of considerable thickness, as in most forms 

 of the compound CyaihophyUidce. Full-grown polyps, measuring about half 

 an inch in diameter, but usually somewhat smaller ; the prevailing size be- 

 ing about three-eighths of an inch. Calyces deep, abru^jtly declining from 

 the intercelkdar walls to a depth nearly equalling the transverse diameter. 

 Longitudinal septa or rays well developed, extending about one-third, or 

 less, of the diameter of the tube from the outer wall, and averaging about 

 forty in number in adult individuals ; some containing thirty-six, and one 

 large one counted gives forty-two. Crest of the rays strongly denticulate, 

 the denticles being thickened and knot-like at their junction with the rays. 

 Central chamber within the limits of the longitudinal rays, equal to one- 

 third of the entire of the polyp, and divided by numerous distinct transverse 

 tabuke, Avhich are variously bent or interrupted by contact with the adjoin- 

 ing ones, leaving irregular cavities of considerable size between them. In- 

 terseptal spaces occupied by a series of horizontal plates, which originate at 

 the outer wall, and extend upward and inward with increased growth to 

 the edge of the rays, where they form the denticulation of the crest. Be- 

 tween the latter plates, the spaces are occupied by the smaller irregular 

 vesicular structure. 



* Named iu honor of Mrs. Ortori, wife of President Orton, of the State University, Columbus, 

 Ohio. 



