100 TABULATE CORALS. 



has not yet been recognised as British, though it will doubt- 

 less yet be found to be represented in our area. 



Striatopora Linneana, Billings. 



(PI. v., figs. 2-2 d.) 



striatopora Linneana, Billings, Canad. Journ., new ser., vol. v. p. 253, 

 fig. I, i860. 

 „ Linneana, Nicholson, Rep. on the Palaeontology of Ontario, 1874, 



P- 59- 

 „ Linneana, Rominger, Foss. Cor. of Michigan, p. 59, PI. XXIII. , 



figs. 5 and 6, 1877. 



Spec. Char. — Corallum dendroid, of dichotomously-branched 

 cylindrical stems, which have a diameter of from two to five 

 lines. Corallites polygonal, diverging from the central line of 

 the branches in gentle curves to open on all points of the free 

 surface, their walls greatly thickened by the growth of a de- 

 posit of sclerenchyma, which increases in amount towards their 

 expanded mouths. Calices of very unequal dimensions, the 

 larger ones mostly about one line in diameter, the younger 

 ones of all sizes, intercalated uniformly among those of full 

 growth. The margins of the calices are polygonal and thin, 

 and surround a funnel-shaped or cup -shaped cavity which 

 opens below by a contracted circular orifice into the proper 

 tube-cavity. The thickened neck of the tube exhibits radiating 

 septal ridges or spines, which are continued throughout the 

 length of the tube, but the outer cup appears to be smooth. 

 Tabulae few, remote, complete. Mural jDores moderately nu- 

 merous, irregularly distributed. 



Obs. — There is little need to add any remarks to the above 

 description, all the essential characters of the species being 

 further shown in Plate V., figs. 2- 2 d. All the specimens I 

 have seen are fragmentary, and are in the form of cylindrical 

 or slightly-compressed stems (PI. V., fig. 2), which evidendy 

 subdivide only at considerable intervals, as often no branch can 

 be observed. When not filled up with adherent matrix, the 

 calices (PI. V., fig. 2 a) at once show the characters of Striata- 



