14 Prof. H. A. Nicliolson on some new or 



In minute structure L. oMoensis presents nothing very 

 special. Owing apparently to imperfect preservation the 

 axial canals of the pillars are only occasionally recognizable ; 

 but I have seen traces of a cribriform structure of the tissue 

 of the pillars. In the specimen which I figured originally 

 the actual skeleton of the fossil has been replaced by calcite, 

 all the cavities of the coenosteum being filled with matrix. 

 In the specimen here figured (for whicli I am indebted to the 

 kindness, of my friend Mr. Arthur H. Foord) the skeleton is 

 preserved in the normal manner. 



Mr. Foord has also drawn my attention to the fact that 

 some of the appearances which he described (Contrib. to the 

 Micro-Pal. of the Cambro-Silurian Rocks of Canada, p. 25, 

 1883) as characterizing Tetradium huronense^ Bill., sp., are 

 really due to the fact that the specimens of this coral which he 

 examined were covered with a crust of LahecMa oMoensis. 

 Thus the granules or tubercles described as covering the 

 surface of Tetradium huronense are referable to the investing 

 Stromatoporoid and not to the coral itself. 



While these pages have been going through the press I 

 have received from Mr, E. O. Ulrich a copy of his ' Con- 

 tributions to American Pal£eontology ' (vol. i. no. 1, May 1, 

 1886), in which a species of ZaZ'ec/jz'a is described from the 

 Cincinnati formation under the name of L. montifera. Mr. 

 Ulrich's description and figures seem to render it certain that 

 the species named &c. is identical with the one to which I had 

 previously applied the name of L. ohioensis. In all essential 

 points the internal structure of these is the same, though Mr. 

 Ulrich's specimens seem to have been in some respects in a 

 better state of preservation than those which have come under 

 my notice. According to Mr. Ulrich the species occurs in the 

 upper part of the Cincinnati group in Ohio and Indiana. 



Formation and Locality. Cincinnati group, Waynesville, 

 Ohio {coll. H. A.Nicholson)] Hudson-River formation. Cape 

 Smythe, Lake Huron [coll. A. II. Foord). 



LahecMa canadensis^ Nich. & Murie, sp. 

 (PI. II. fig. 5.) 

 Stromatocerium canadense, Nicholson & Murie, Journ. Linu. Soc, Zool. 



vol. xiv. p. 223, pi. iii. fig-s. 9, 10 (1878). 

 Labechia canadensis, Nicholson, Mon. J3rit, Stromatoporoid*, pi. ii. 

 figs. 3-5. 



Coenosteum sometimes massive, sometimes composed of 

 thick laminte with a basal epitheca. Surface imperfectly 

 known, but apparently possessing irregular tubercles and 

 conical mamelons. Radial pillars large and irregularly deve- 

 loped. The vesicular tissue between the pillars is also very 



