SECONDARY AND TERTIARY FORMATIONS OF NORTH AMERICA. 153 



The accessory cells appear to be ordinary cellules undeveloped, and are not always 

 placed immediately in advance of an ordinary cellule. They are about two-thirds of 

 the ordinary size, not closed above, by a testaceous covering, but have tie anteiior 

 edge very much produced, thin and overhanging, and about as high as the length of 

 the aperture. We have noticed but one broken ovarian vesicle, which is placed in 

 advance of the cellule to which it belongs, appears to have been semiglobular and 

 overlaps the proximal surface of the succeeding cellule, reaching to the edge of the 

 aperture. 



We think this is the form figured by Lonsdale under the impression that it was the 

 immature state of Eschara cligitata, in figures a and b, (see remarks under that species.) 

 The form is very constant ; very compressed, twisted branches with large oral open 

 ings arranged in distinct longitudinal lines. The young state of K digltala never 

 presents the open character of cellules such as we see in this species. Besides, the 

 form of the cellule is very distinct. 



Tlie form of the cellules is generally pretty constant, but in a few instances we 

 have noticed extraordinarily elongated forms, produced apparently by the neighboring 

 cellules having crowded the deformed one so that it had no space for development 

 except anteriorly. The cellules, which we have termed accessory, differ from the 

 ordinary ones in being smaller, and in having the anterior end developed into a promi- 

 nent overhanging lip. Being usually placed in advance of ordinary cellules, we at 

 first supposed them to be the ovarian cells, but on discovering the remains of one of 

 the latter organs we are obliged to change the opinion. What the function of this 

 curious modification of the cellule is, rests with students of the recent forms to deter- 

 mine by examination of living specimens. We have not yet encountered them among 

 living species. 



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



B. disjuncta, n. s., fig. 37. — Colony compressed, composed of robust cells, placed 

 back to back in a somewhat alternating manner, and very loosely connected by the 

 backs and laterally. The cells of the same longitudinal series are intimately con- 

 nected by a fusion of the testaceous substance. Cells hexagonal, placed in regular 

 longitudinal rows and in quincunx. Opening terminal, oval, somewhat variable in 

 form and with the basal wall of the cell sloping upwards, blending with the surface in 

 such a manner as to obliterate nearly or entirely the anterior margin of the opening. 

 The aperture occupies about two-thirds of the anterior part of the cellule. Surface 

 plain, slightly rounded inwards around the mouth and outwards at the constriction 

 between the cells in the same longitudinal line. 



Found with the preceding. 



The slight adhesion laterally and by the backs of the cellules renders it difficult to 

 ascertain the mode of growth of this species. The specimen figured, and another series 



