SECONDARY AND TERTIARY FORMATIONS OF NORTH AMERICA. 131 



superiorly, except a slight undulation of the surface. Surface coarsely perforate by 

 large irregular pores placed close together; anteriorly prolonged into a large trumpet 

 shaped tube. This tube is inclined upwards and forwards, is expanded at its extrem- 

 ity, around the mouth, and the lower portion, for from one to two-thirds of its length, 

 is marked by impressed stria? having a spiral tendency. The lateral and terminal 

 walls are thin and perforated by vejy distinct connecting pores. 



Locality. — With the preceding, encrusting Idmonea Californica. Rare. The tubu- 

 late mouths of this species gives it a striking resemblance to Entalophora punctata, but 

 it can be distinguished by the fact that it is encrusting, while the latter is in dendroid 

 branches. The very exsert mouths might lead one to suppose that this beau- 

 tiful little Polvzoon was a centrifuginate, but we are satisfied that the cellules arise 

 from the sides and ends of the preceding ones, and not from behind them, as is the 

 case in the latter order. The tubes sometimes are almost decumbent on the surface 

 of the succeeding cellule, but usually rise at a slight angle. There is no thickening 

 around the mouth. 



REPTOCELLEPORARIA, d'Orb. 1851. 



Colony testaceous, encrusting submarine bodies, never raising in free plates or 

 branches, but composed of numerous layers superposed. Cellules, same as in Cellepora 

 and other Escharidse. Ovarian vesicles not uncommon. 



Differs from Cellepora in having many layers superposed, instead of only one; from 

 Celleporaria in that, while composed of numerous layers, it is always encrusting, never 

 rising into dendroid branches. 



R. aspera, n. s., fig. 14. — Colony encrusting usually composed of from four to twenty 

 layers, sometimes presenting a knotted or coarsely tuberculose surface. Cellules oval 

 to rounded hexagonal, placed irregularly, but with a tendency to a general arrange- 

 ment in one direction in the same neighborhood, convex and very prominent on the 

 surface, separated by deep irregular depressions. Mouth anterior, not terminal, semi- 

 circular to subquadrate, with the angles rounded, sometimes elongated, but usually 

 with the proximal edge straight or curved outwardly, and always with the greatest 

 diameter placed transversely. Surface of the cellules marked by a small number of 

 large rounded elevations placed irregularly, and with those nearest to the edge elon- 

 gated so as to present between them grooves, resembling remotely the fossets of the 

 Eivliarellidce. These grooves are continued all round the edge of the cellule, and at 

 their extremities we can generally observe a small pore, piercing the crust. 



From the cretaceous of Timber Creek and near Mullica Hill, N. J. The pores 

 around the edge, placed in distinct grooves, at first caused us to hesitate in placing 

 this species in the above genus; but on a more thorough examination, we are con- 

 vim cd that they are no more like the "special fossets" of d'Orbigny, than are the 



34 



