NIAGARA GROTJT. 



151 



541. 3. TREMATOPORA TUBULOSA (n. sp.). 



PL. XL A. Fig. 3 a, b, c. 



Corallum consisting of cylindrical or flattened stems, solid or having the interior filled with 

 mineral matter ; cells closely arranged, opening upon the surface by minute oval apertures, 

 and margined by elevated borders which are more projecting on the lower side ; transverse 

 section showing a fibrous structure. 



This coral differs from the preceding, in having more closely arranged apertures opening 

 obliquely upward, with the border on the lower side more projecting. The coral is a hollow 

 cylinder, the interior being filled with stony matter ; but this condition occurs in many species 

 of this genus. 



Fig. 3 (7. A fragment of a stem of the natural size. 



Fig. 3 6. A section of the end of the stem. 



Fig. 3 c. A portion of the surface enlarged, showing the form and arrangement of cells. 



Position and locality. Green shale of the Clinton group, Wayne county. 



This species is arranged with its congeners in this place, in preference to giving it by itself 

 with the corals of the Clinton group. It is the only one of the genus known below the Niagara 

 shale. 



542. 4. TREMATOPORA PUNCTATA (71. 5;>.). 



PL. XL A. Fig. 4 a, b, e. 



Coral incrusting, composed of cylindrical tubular cells which open upon the surface in cir- 

 cular apertures ; apertures closely arranged ; internal structure showing the cylindrical tubes 

 and septate interspaces. 



This coral is only known as incrusting crinoidal stems, several specimens having been found 

 in this condition. It differs from either of the preceding species in the circular apertures, which 

 are usually closely arranged, giving the surface a punctate character. In worn specimens the little 

 marginal elevations around the aperture are often obliterated, and the stem is smooth with 

 the small round pores penetrating its surface. The apertures are sometimes slightly separated 

 from each other, and the arrangement, though apparently uniform, is nevertheless, under a 

 magnifier, sho^vn to be variable. 



Fig. 4 a. A coral of this species enveloping a fragment of a crinoidal stem. 



Fig. 4 i. A portion of the surface enlarged, showing the form and arrangement of the apertures^ 



which are sometimes close together and in other parts separated. 

 Fig. 4 e. A section of the stem enlarged, showing the structure of the coral. 



Position and locality. In the soft shale of the Niagara group at Lockport. 



