344 CRETACEOUS PALEONTOLOGY. 



Membraniporella distans (Gabb and Horn). 

 Plate XXV., Fig. I. 



1862. Bsckoripora distans G. & H., Jour. Acad. Nat. Sci. Phil., 



2d ser., vol. 5, p. 148, pi. 20, fig. 32. 

 1864. Escharipora distans Meek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 3. 

 1868. Escaripora distans Con., Cook's Geol. N. J., p. 722. 



Description. Zoarium robust, apparently consisting of a tor- 

 tuous, anastomosing series of plates with zooecia on both sides. 

 Zooecia small, elongate, often acuminate at the proximal end, 

 arranged in longitudinal lines and quincunx, apparently sepa- 

 rated longitudinally sometimes to the extent of the length of a 

 zocecium ; the longitudinal series are very close together and 

 occasionally, though rarely, the ornamented portions of two 

 zooecia occur without any depression between them. Zocecial 

 apertures" small, round, oval or subquadrate, usually bordered by 

 a thickened raised lip which is usually continued around the 

 avicularia and disappears towards the proximal end. Outer wall 

 of the posterior portion of the zooecia not differentiated from the 

 general surface of the zoarium, but just back of the aperture there 

 is an elongate, subelliptical, differentiated area which is pierced 

 by 10 or 12 slit-like pores directed at right angles to the margin 

 of the elliptical area, leaving a central imperforate space. Avicu- 

 laria small, subovate or subelliptical, situated one on either side 

 of each zocecial aperture, from the margin of which they are 

 directed obliquely outward and backward* Ovicells large, elon- 

 gate, rounded anteriorly and generally constricted near the 

 zocecial aperture, marked above by an impressed circle or ellipse 

 which circumscribes a hemispherical portion covering the larger 

 part of its surface. 



Remarks. This species is imperfectly known as it has not been 

 met with in the recent collections and the original specimen seems 

 to have been lost or destroyed. It seems to be characterised, 

 however, by the apparent separation of the zocecia in the longi- 

 tudinal series upon the surface of the zoarium, and also by the 

 large hemispherical oviceJJs. 



