532 LONSDALE ON EOCENE CORALS FROM N. AMERICA. 



This fossil resembles, in the arrangement of the cells and 

 the form of the opening, Lunulites radiata and L. urceolata as 

 figured by G-oldfuss (Petref. 12. f. 6 and 7.), but it differs from these 

 species in its great relative size, and, so far as its state of preser- 

 vation would permit of a comparison, in many of its structural 

 details. 



The specimens consisted almost wholly of casts of the interior of 

 the cells, of the intermediate radiating plates, representing appa- 

 rently grooves between the rows of cells, casts of the minute 

 connecting channels, and impressions of the concave surface. The 

 diameter of one of the larger specimens was 11 lines, and the 

 depth of the cone, in the original, was probably 5 lines; but 

 different specimens varied considerably in the relative measure- 

 ments. Some fragments presented also great irregularities along 

 the lines of renewed growth ; and casts of vermiform as well as 

 elliptical perforations (containing in one case a minute lithodomous 

 shell) frequently occurred in the space between the layer of cellular 

 casts and the concave surface. The only specimen of the convex 

 exterior which was examined was greatly worn, but it exhibited 

 oval openings equal in dimensions to the area of the cells ; and in 

 some fragments, where casts of the cells had been removed, the 

 same want of an exterior covering was exposed (fig. c). In this 

 respect L. distans agreed with other species, having the cells simi- 

 larly arranged in radiating, non-alternate rows. Professor Gold- 

 fuss, however, states that the middle cells of L. radiata were 

 closed, but he does not allude to a distinct oral aperture in the 

 covering — a character which has been noticed in one specimen of 

 a Lunulites with similarly arranged cells ; and which is often 

 strongly exhibited in species with alternate rows.* The filiform 

 processes representing the foramina which connected the cells 

 (fig. c), ranged, in consequence of the partially overlying position 

 of the casts, from the upper side of one to the under side of the 

 next, when the specimen was placed with the apex downwards, 

 and they differed not in character from the other processes or 

 casts of minute channels which passed from the uncovered pro- 

 jecting part of the cell to the concave surface (fig. b, c). Similar 

 filaments extended laterally to the dividing plates. In general, the 

 separating laminae were much broken, but in some cases they 

 ranged continuously between the two surfaces of the specimen. 

 The additional rows of cells were irregularly interpolated on the 

 lines of the dividing plates. No very clear signs of intermediate 

 chambers, or shallow circular cavities, between the rows of cells 

 were exhibited ; but on the fragment which gave imperfectly the 

 convex surface, faint indications were detected of depressions 

 similar to those exhibited by Goldfuss in plate 12. figures 6 and 7 

 of the Petrefacta German., and by other authorities who have 



* Consult figures of Lunulites umbellata, &c, referred to in the notice on the 

 Miocene Lunulites, anti, p. 504. 



