new Species of Stromatopora. 93 



pillars, which are disposed at right angles to the lamina? and 

 mark off minute cellular compartments or interspaces. The 

 lamina? and intervening spaces are about five in the space of 

 a line ; and the vertical pillars are comparatively strong, and 

 placed at proportionally remote intervals. The upper surface 

 of the mass (PL IV. fig. 2) is more or less strongly undulated, 

 and is covered with close-set, conical, clavate, or fungiform 

 tubercles, the elevation of which is about one twenty -fifth of 

 an inch above the general surface. The tubercles appear to 

 be sometimes perforated, but are more commonly imperforate, 

 and they are placed in irregular sinuous lines. They are 

 separated from one another by about their own width (more or 

 less), one twenty-fifth of an inch. Where this fossil is broken 

 it is seen that similar tuberculated surfaces occur at various 

 depths in the mass, concentric with one another, and separated 

 by laminated and reticulated tissue. 



This singular species is readily distinguished by its very 

 coarse reticulation (coarser than in any other species of Stro- 

 matopora with which I am acquainted), and by the tuberculated 

 nature of the surface. There is no proof that the vertical 

 pillars which separate the different laminae of the mass are 

 hollow ; and there is reason to believe that they are cer- 

 tainly solid. As a rule, also, no perforations can be detected 

 in the surface-tubercles ; and the true nature of the latter is thus 

 rendered a matter of question. In some specimens, however, 

 the tubercles appear to be distinctly perforated at their apices. 

 Many examples exhibit rounded openings or tubes, from half 

 a line to a line in diameter, descending at right angles to the 

 mass, and placed at varying intervals. These openings are 

 not elevated above the general surface. They are not constant 

 in their occurrence, though very generally present ; and I have 

 not been able to satisfy myself that they are not truly extra- 

 neous to the fossil. They may, perhaps, be annelidous in 

 their nature ; or they may be due to the fact that the organism 

 has enveloped a colony of Syringopora, which has subsequently 

 been dissolved away. In one specimen the crust seems to 

 have been supported upon a wrinkled calcareous base, very 

 similar to the epitheca of Favosites gothlandica. The crusts 

 vary in thickness from three or four lines to two inches or more ; 

 but the latter specimens are to be regarded as being composed of 

 a succession of crusts superimposed, the younger upon the older* 



Loc. and Form. Common in a silicified condition in the 

 Corniferous Limestone (Devonian) of Ridgeway and Port Col- 

 borne, on the north shore of Lake Erie, Canada West. 

 Collected by the author. 



