134 MONOGRAPH OF THE FOSSIL POLYZOA OF THE 



through a lens, separates it readily from R. informata. Miocene, (" Pliocene " Holmes) 

 Virginia and South Carolina. 



E. umbilicaia d'Orb. (Cellejpora, id., Lonsd. is a Multiporina.) 



R. glomerata, n. s., fig. 15. — Colony composed of many superposed layers of cel- 

 lules. Cellules placed irregularly ; oval, convex, separated by depressed lines. Open- 

 ing anterior or nearly central, round to subquadrate, simply pierced, not bordered by a 

 few round pores, near the margin, sometimes only posterior to the mouth, at others, 

 surrounding it and occasionally scattered over the surface. Dividing walls thick, 

 separated. 



The above description was taken from two, much worn, colonies, hardly showing 

 more cellules than those figured. On all the cellules, we observed, near the mouth, 

 and invariably bebind it, a subquadrate, oval, or semilunar depression, in one in- 

 stance, appearing to have been bordered by a wall, perhaps the remains of an arched 

 vesicle. We could detect no connection between this depression, and the interior of 

 the cellule. Owing to the worn condition of the specimens, we may have omitted 

 some of the specific characters ; but the short, oval, very convex form of the cellules 

 will distinguish this species from any yet known. 



Locality. — Vicksburg, Mississippi, Eocene, associated with Oligotresium Yiclcs- 

 buryensis. 



Sub-Fam. ESCHARELLIN.E, d'Orb. 1851. 



ESCHARIFORA, d'Orb. 1851. 



Colony sometimes encrusting in its earlier age, afterwards rising in free plates or 

 compressed branches, with cellules on both faces, separated by a median germinal 

 plate. Cellules of two kinds, — ordinary and accessory. Ordinary cellules placed in 

 longitudinal lines and quincunx, opening small or of moderate size, placed in the cen- 

 tre of the cellules and surrounded by a number of fossets, or of pores performing the 

 function of special fossets. The accessory cellules differ from the ordinary ones in 

 the form of the aperture, which usually exposes the greater portion of the cellule. 



It will be observed that we have modified the description of this genus in one im- 

 portant particular. We have observed a character, not altogether new in the mode 

 of growth of the polyzoa. In other words, the following species, like the genus 

 Diastopora, sometimes encrusts for a considerable distance before rising from the en- 

 crusted surface. In this case the cellules are placed in two series back to back, while 

 in Diastopora they are in only one layer. 



E. ttpica, G. and H., fig. 16. 



Cellepora typica, G. and H., Proc. Acad. 1860, p. 366. 

 C. typica, G. and H., Jour. Acad. 2d s. vol. 4, p. 400, pi. 59, f. 27—29. 

 Colony encrusting; sometimes in patches nearly an inch across, in its early age; 



