48 PALEONTOLOGY OF NEW-YORK. 
Genus STROMATOCERIUM. 
In the black marble of Ile la Motte, and in the same rock at Chazy, but more particularly 
in the dark limestone containing the Cotumnanria, we find numerous specimens of obscure 
corals having a structure represented in figs. 2, 2 a and 6. They are completely silicified, 
so that the more minute structure cannot be decided ; but since they are abundant, and 
require notice, I have proposed the provisional name of Stromatocerium, from ¢rpuya, -aros, 
a layer or lamina, and xxpiov, honeycomb. 
81. 1. STROMATOCERIUM RUGOSUM. 
Pu. XII. Figs. 2, 2 a, b. 
Coral hemispherical; growth in concentric laminz or strata ; lamine numerous, wrinkled; 
some faint indications of vertical tubes or cells. 
This coral usually appears as a rough shapeless excrescence upon the weathered surface 
of the limestone ; but a little examination shows it to be composed of concentric layers, 
which are evidently the skeleton of some coral. 
Fig. 2. A specimen, natural size, showing the concentric lamination of the coral. The masses are often 
several times as large as this one. 
Fig. 2 a. A fragment magnified, showing less contortion of the lamin, with some indistinct indication 
of vertical tubes or cells. 
Fig. 2 6. A small portion of a specimen of the natural size, showing the rugose or contorted direction 
of the lamine. 
Position and locality. This coral, so far as known, is confined to the Black-river limestone, 
and to the dark layers alternating with the Birdseye limestone. It occurs in the dark marble 
quarried on the east side of Ile la Motte; but this mass les much above the Maclurea 
magna, if not higher than the Birdseye limestone. It occurs at Chazy village, Watertown, 
and other places. 
82. 2. CHATETES LYCOPERDON? 
Pu. XII. Figs. 3, 5: 
See Plates xxiii. and xxiv. Trenton limestone corals. 
A cylindrical branched coral; branches somewhat clavate ; tubes fine, angular ; no 
connecting pores visible. 
There is no apparent difference between this species and the one so common in the 
Trenton limestone. It is extremely rare in the Birdseye, though I have been led to suspect 
its existence in many instances where the structure is wholly obliterated by crystallization, 
as is the case with many other fossils of this rock. The same fossil, apparently, occurs in 
worn ovoid fragments in the Chazy limestone, and its upward limit I have not yet as- 
certained. It has, however, evidently a wide geological range; coming into existence at 
almost the earliest period of organic life, and is among those rare forms that escaped de- 
struction, or again came into existence after the final deposition of the Hudson-river group. 
