SECONDARY AND TERTIARY FORMATIONS OF NORTH AMERICA. 135 



afterwards rising in free flattened branches, generally branching all in the same plane, 

 sometimes tortuous. Ordinary cellules broadly oval, form visible only in the youngest 

 portions of the colony, in ordinary adult colonies the surface being uniform. Mouth 

 rounded anteriorly, straight on its proximal margin ; immersed, with the sides abruptly 

 sloping, and a slight rim at the inner edge. Sometimes at the proximal edge a tooth- 

 like process, which is occasionally bifid at its extremity ; in one instance we noticed 

 another tooth springing from the anterior lateral margin and directed towards the 

 centre. Accessory cellule observed in only one instance, substituted in the place of 

 an ordinary one, and differing in having the aperture larger, very elongate and nar- 

 row at the distal extremity. In this case the immersed character of the mouth, and 

 the small rim immediately bounding it, are better exhibited on account of the larger 

 size of the opening. The special fossets in this species are represented by five tubu- 

 late pores, one placed in advance and the other four at the angles of the oval opening, 

 not always at regular intervals. The surface of the colony is slightly undulated, and 

 generally depressed towards the mouths of the cellules. 



From the Cretaceous, Timber Creek, Mullica Hill, and in one instance, the speci- 

 men first described, from the upper portion of the second division of the Cretaceous 

 following the divisions in the Geological Reports of New Jersey; the Timber Creek 

 beds belonging to the highest division. 



The first described specimen of this species shows no signs of the tendency to a free 

 portion of the colony, and the pores surrounding the mouth having been almost ob- 

 literated, we considered it a Cellepora. Having since procured a large number of 

 specimens, some in a very perfect state of preservation, we are able, happily, to deter- 

 mine the true position of this most remarkable form. One specimen in our possession 

 places the identity of the encrusting and free portions beyond a doubt, since it shows, 

 as represented in figure c, the surface sloping up on both sides, uniting, with a germi- 

 nal plate between them, and rising prominently from the surface of the encrusting 

 plate. When we add to this the fact that in the most minute structural detail both 

 forms agree precisely, there can be no reason for doubting their identity. 



In broad specimens we have noticed that the quincuncial arrangement of the cel- 

 lules is modified, so that lines drawn across the intersecting rows of mouths are 

 curved outwardly instead of being perfectly straight. 



ESCHARELLA, d'Orb. 1850. 



Colony resembling Escliara in its mode of growth, composed of cellules arranged 

 back to back and in longitudinal lines and quincunx. Cellules of two kinds — ordinary 

 and accessory. Ordinary cellules have the mouth in advance, exposing but a small 

 portion of the interior ; behind the mouth are placed special fossets, arranged radiately 



35 



