ir • 



BLACK-KIVER LIMESTONE. 49 



Fig. 3. Specimen natural size. 



Fig. 4. Probably the same species, very minute, occurring in some thin shaly layers at the upper part 

 of the Birdseye limestone, or at its junction with the Black-river limestone. 



Position and locality. Upper part of the Birdseye, and in the Black-river limestone, at 

 Watertown, JefTerson county. 



83. 2. STREPTOPLASMA PROFUNDA (n.*p.). 



Pl. XII. Figs. 4 a, b, e, d. 



Obliquely turbinate, often slightly curved near the base, expanding above more or less 

 abruptly ; cell profoundly deep, extending nearly to the base of the coral ; margin of the 

 cup reflexed ; surface scarcely marked by transverse ruga ; lamellae from 36 to 60, strong, 

 nearly equal on the margin, but distinctly alternating in length within ; no transverse 

 dissepiments or celluliferous structure. 



Specimens of this fossil occur in considerable numbers in the upper part of the Birdseye 

 limestone, and in the Black-river limestone. One specimen in the State Collection presents 

 the remains of more than sixty individuals upon a surface six inches square. 



This fossil never presents any evidences of budding from its centres, as in many of the 

 CTATHOPHTLLiE ; for amoug all yet seen, the individuals are single and distinct. When 

 worn down longitudinally or obliquely upon the surface of strata, as in figs. 4 d, e, and 

 similar forms, they have been regarded as the jaws and teeth of fishes, and this has given 

 rise to the report of remains of fishes in these lower strata. The interior of the cup presents 

 a serrated appearance, which is owing to oblique sections that are shown in the figures just 

 referred to. 



Fig. 4. Lateral view of a specimen where the edge of the cup is worn down, shortening the entire length 



about one-third. 

 Fig. 4 a. Section of a specimen near the base, showing the contortion of the lamellae at the centre : the 



section is slightly oblique. 

 Fig. 4 h. Transverse section above the base, showing the alternation of larger and smaller lamellae, 



which do not reach the centre. 

 Fig. 4 e. Transverse section near the termination of the cup. 



I have some doubt whether the section here presented is of the same species, the lamellae 



being much stronger and less in number than in the other individuals, which all occur in 



one specimen of the stona 

 Fig. 4 i. A longitudinal section, slightly oblique to the axis, and coming out on one side of the centre 



below, showing some of the lamellae vertically and others obliquely — giving the serrated 



appearance before alluded to. 

 Fig. 4 e. An oblique section, being nearly transverse to the lower part of the fossil on one side. 



Various other appearances are given by these natural sections on the weathered surfaces 



of the limestone, which are exceedingly instructive as illustrating the generic and specific 



characters of the coraL 



Position and locality. Watertown, in the " 7-foot tier ; " Chazy ; He la Motte ; also in 

 great numbers at Manheim, East-Canada creek, in the Birdseye limestone. 

 [ Pal.«ontology.] 7 



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