158 MONOGRAPH OF THE FOSSIL POLYZOA OF THE 



calcareous plate, perhaps the membrane changed by a deposit of lime. This plate is 

 flat, except in the middle, where there is a thickened rim, bounding a very small 

 mouth. Surface of the cellule rounded, most elevated behind the aperture, from which 

 point the surface slopes in all directions with a gentle curve. The aperture is placed 

 at the base of a slight depression, and is sometimes bounded, especially at the proximal 

 side, by a faintly thickened lip. Between the cellules, and without any regular ar- 

 rangement, are placed, in most colonies, large numbers of abortive cellules, of the 

 same shape as the larger ones. In some colonies these abortive cells are full as 

 numerous as the normal ones, and only in a very few instances have we observed 

 colonies to be entirely without them. When the latter is the case, the normal 

 cellules are much more regular in size and in arrangement. 



Common in the Cretaceous limestone of Timber Creek, and near Mullica Hill, N. J. 



M. perampla, n. s., fig. 42.— Colony composed of encrusting cellules, very large, 

 distinctly visible to the naked eye, disposed in an irregular quincuncial order; variable 

 in shape, usually rounded in advance and frequently encroached on laterally and 

 posteriorly by neighboring cellules. Edge somewhat elevated, surface sloping inward 

 on all sides towards the aperture, which is large and irregular. No ovarian vesicles 

 were observed. Sometimes behind the orifice is a regular depression, parallel with 

 its margin. 



Near Mullica Hill, N. J. Cretaceous. 



The above description was taken from a single specimen. There are several others 

 before us, resembling this in most of their general characters, but with the cellules 

 oval to subhexagonal, often separated by a distinct impressed line, with the orifice 

 large and elliptical. We believe them to belong to this species, but cannot so refer 

 them positively. The latter form has sometimes a raised lip behind the aperture, as 

 shown in one cellule of our figure. This, with the fact that the cellules are of the 

 same size, and that the aperture is somewhat variable, has induced us to suspect their 

 specific identity. They are, at least, very closely related. 



M. plebia, n. s., fig. 43. — Colony composed of encrusting cellules generally arranged 

 with a tendency to radiating lines, and in irregular quincunx. Cells elongated to 

 pyriform, separated by distinct depressed lines, sometimes widening so as to form 

 small open spaces. Opening occupying the whole cellule, walls very narrow, without 

 any markings, appearing to overhang the internal cavity very little if at all. Some- 

 times the proximal edge is slightly widened and concave, at other times it is a little 

 convex. Ovarian vesicles not uncommon ; small, convex in front, but slightly 

 elevated and occasionally with an obsolete longitudinal carina. At times we find 

 the cellules separated longitudinally, and a small abortive cellule placed between 

 them. 



From near Mullica Hill, N. J. Cretaceous. 



