Palcontoloiiy of the Cincinuati (tjoiip. 153 



this place may lead lo the discovery or identification of other 

 specimens. 



Genus 2. — TirrKADH'M, Dana, 1846. 



Corallum massive, composed of long, i)rismatic and closely 

 contignous corallites, without mural pores; septa distinct, 

 few, generally four, short, not reaching to the center of the 

 visceral chamber, appearing like inflections of the wall ; 

 calices generally petaloid ; tabulae numerous, complete ; in- 

 crease apparently by fission of old tubes. (U. S. Explor. 

 Exped., vol. 8, Zoophytes, 1846, p. 701 ; Nicholson, Pal. Tab. 

 Cor., 1879, p. 231.) 



Remarks. — The above is Nicholson's description of the 

 genus. That given by Dana, although short, covers the main 

 points. It is as follows: "Corallum massive, consisting of 

 four-sided tubes, and cells with very thin septa or parietes ; 

 cells stellate, with four narrow lamellae." Safford made the 

 following remarks later on : (Am. Jour. Science, 2d ser., vol. 

 22, 1856, p. 236.) "The tubes in the different species vary 

 from y{ of a line to nearly i line in breadth ; they are \^xj 

 long, and are most frequently united throughout laterally, 

 forming massive coralla, resembling, more or less, those of 

 Favosites and Clurlctcs: sometimes, however, they are united 

 in a single intersecting series, as in Ha ly sites catenulata, Linn.; 

 not unfrequently, too, the tubes are isolated, or only united at 

 irregular intervals, thus forming loose fasciculated coralla, 

 resembling certain forms of Syringoporay 



I. — T. FiBRATi'M, vSaflford, 1856. 



" Coralla massive, hemispherical or flattened hemispherical, 

 composed of diverging tubes; cell tubes four-sided, with thin 

 and slightly rugose walls ; the four lamellae distinct, nearly 

 reaching the center of the tubes; breadth of full-grown tubes 

 usually about, or but little more than Yz a line, varying occa- 

 sionally from ' 3 to ^ of a line ; transverse septa usually 

 absent; a few have been seen in one specimen, which were 

 about twice the breadth of a tube apart." (Am. Jour. Sci., 2d 

 ser., vol. 22, 1856, p. 237.) 



Locality. — Oxford, Ohio, and other places in the upper beds 

 of the group. 



