NIAQARA eKOUP. 



145 



Where the surface is worn, the intercellular spaces often appear to be solid, and a vertical 

 section shows no cellular character : transverse sections of the stems sometimes show the con- 

 tinuance of the intercellular spaces to the centre of the stem. 



In well preserved specimens the cells are transversely septate, though the septa are rarely- 

 preserved in the open tubes, and are best shown in partially weathered crystalline specimens. 

 In the greater number of specimens the apertures of the cells are quite open ; while a small 

 number of specimens (and in others a few of the apertures), have a smaller circle or point in 

 the centre, with six or seven rays diverging therefrom. This character, however, cannot be 

 relied upon, as these rays appear to be deciduous, and are preserved only in the most perfect 

 specimens. 



Fig. 1 a. The base of a specimen, showing numerous diverging stems which are irregularly 

 branched. 



Fig. 1 6. A continuation of some of the branches of the last specimen, showing an individual of 

 Cladopora mxtltipora, attached and growing from the stems of this coral. 



Fig. 1 c. A fragment showing the circular openings unequally distributed over the surface. 



Fig. 1 d. A smaller bifurcating branch, having the cells more evenly distributed. 



Fig. 1 e. A fragment showing the hollow terminations of the branches. 



Fig. 1/. A fragment enlarged where there are no circular apertures on one side, a striated or 

 minutely cellular surface alone existing. The transverse section of the stem in the 

 annexed figure shows that the increase of growth was made mostly on one side, and 

 this side is the one on which the tubular cells exist, while that side represented in 1 

 / has increased very little. 



Fig. 1 ^- A fragment having a tortuous or irregular form, caused by contraction from the oblite- 

 ration or cicatrizing of the cell apertures, and consequent cessation of growth at these 

 points. 



Fig. h. An enlargement at one of those points where growth has ceased, and the intercellular 

 space appears to be solid or simply striated upon the surface. 



Fig. 1 i. An enlargement of 1 c, showing the irregular distribution of the apertures of the cells. 



Fig. 1 ^. A similar enlargement where the cells are in contact. 



Fig. 1 I. An enlargement showing the stellate apertures, with another figure somewhat more 

 highly magnified than the preceding. 



Fig. 1 m. An oblique section of a stem enlarged. 



Fig. 1 n. An enlarged portion of the section of another stem, showing the transverse septa 

 crossing the intercellular spaces, with a single tubular cell crossed by several septa 

 in the lower part. 



Position and locality. This species is very common in the shale at Lockport, and occurs 

 likewise in the lower part of the limestone at the same place. It can be found at the base of 

 the terrace, or in any other situation where the shale has decomposed, leaving the small cal- 

 careous fossils washed out by the rains. instate Collection.) 



[ Paleontology — Vol. ii.] 19 



