10 Beecher — Observations on the Genus Romingeria. 



EXPLANATION OF PLATES. 



Plate I. 



Romingeria umhellifera Billings, sp. 



Figure 1. — Side view of portion of a normal corallite, with a circle of 

 twelve buds at the summit, x 4. 



Figure 2. — Side view of a corallite, with the buds removed; showing the 

 large initial pores connecting the parent with the daughter corallites, and 

 the abrupt constriction of the parent at the budding zone. The serrations 

 of the summit are produced by the proximal ends of the septal ridges, and 

 correspond in number with the buds, x 4. , 



Figure 3. — Top view of the preceding ; showing the twelve initial pores 

 connecting the buds with the parent corallite, and the twelve septal lines 

 extending over the tabula of the parent corallite. x 4. 



Figure 4, — A section of a corallite just above the budding zone ; showing 

 eight distinct septal spines. The center is filled with silica and the full 

 extent of the septa obliterated, x 4. 



Figure 5. — A specimen similar to figure 1, in which, from compression, 

 the walls of the parent corallite have been split into vertical plates, corre- 

 sponding to the septal divisions, x 4. 



Figure 6. — Side view of an umbel from which all but two of the buds 

 have been stripped, leaving their inner walls attached to the central or 

 parent corallite. Two pores are shown on the left side of the figure, com- 

 municating between adjacent buds, and two of the initial pores are repre- 

 sented at the base, x 4. 



Figure 7. — Showing point of contact of two corallites and the formation 

 of a mural pore. x 4. 



Figure 8. — Side view of two closely appressed umbels, causing a suppres- 

 sion of some of the buds, x 4. 



Figure 9. — Top view of the preceding ; showing fifteen corallites. a and 

 b are the two parent corallites. Eleven buds have been suppressed, x 4. 



Figure 10.— Basal view of two adjacent normal umbels of twelve buds 

 each, in close contact, so that there are no interstices between the coral- 

 lites. X 4, 



Figure 11. — Showing the loose interlocking of the corallites from two 

 adjacent umbels, x 4. 



Figure 12. — Side view of an umbel containing eleven buds, x 4. 



Figure 13. — Basal view of the same, x 4. 



Corniferous limestone, near Leroy, New York. 

 Collection, Yale University Museum. 



Plate II. 



Romingeria umhellifera Billings, sp. 



Figure 1. — Basal view of a colony ; showing the characteristic appearance 

 of normal growth. Two-thirds natural size. 



Corniferous limestone, near Leroy, New York. 

 Collection, Yale University Museum. 



Plate III. 



Romingeria umhellifera Billings, sp. 



Figure 1. — An oblique basal view of the specimen on the preceding plate ; 

 showing more distinctly the umbellate habit of growth. Above three-fourths 

 natural size. 



Corniferous limestone, near Leroy, New York. 



Collection, Yale University Museum. 



