ESCHARIDiE. 75 



rostrate avicularium in front of the mouth ; and the presence, pretty generali}^ of an 

 avicularium usually raised on a small papilla at the lower angle of each fenestra on the 

 back of the polyzoary. Although the fragments found in the Crag arc small, very 

 imperfect, and rather rare, yet the characters above mentioned have been satisfactorily 

 made out. It is a living British species, but found, I believe, only on the south and 

 south-west part of the coast, but it is abundant on the Coast of Spain and in the Mediter- 

 ranean ; and a form apparently undistinguishable from it occurs in the Southern Hemi- 

 sphere, together with several others wholly distinct, though much resembling the European 

 species in general aspect. In the absence of any precise account of the minute characters, 

 it is impossible to decide upon the correctness of the various synonyms of fossil Retepores, 

 and those, therefore, only have been introduced which appeared the most likely to be 

 correct. For a similar reason, I have altogether omitted the forms noticed by Goldfuss, 

 his descriptions and figures being wholly insufficient for their identification. His 

 B. vibicata appears decidedly not to be R. cellulosa, the fenestras being too wide, and the 

 dorsal aspect very unlike that of the latter species. 



2. R. Beaniana, Kinc/. PI. XII, figs. 2, 5, 6, and 7. 



Polyzoario infundibuli — seu hypercrateriforrni, undulato; dorso subvibicato, aviculariis, 

 parvis, sparsis munito. Cellulis ovatis seu subcylindraceis, rostro gracili plerumque 

 elongato et avicularium mandibula semicirculari paratum, apice gerente armatis. Ostio 

 orbiculari spina marginali utrinque munito. Ovicellula fissura verticali ornata. 



Polyzoariura infundibuliform or hypercrateriform, wavy ; cells ovate or subcylindrical ; 

 orifice orbicular, with a slender rostrum projecting in front immediately below it, on the 

 summit of which is an avicularium with a semicircular mandible ; an oral spine on each 

 side above ; ovicell with a vertical slit in front ; small avicularia scattered over the dorsal 

 surface, 



MiLLEPORA CELLULOSA, Jameson, Werner Mem., i, p. 560. 

 Retepora cellulosa, Johnston, Mag. Nat. Hist., vii, p. 638, fig. 69. 



— BEANIANA, King, Ann. Nat. Hist., xviii, p. 237, 1846; Johnst., Brit. Zooph., 

 2d ed., i, p. 353, fig. 67, 1847 ; Busk, Brit. M. Cat., part ii, p. 94, 

 pi. cxxiii, figs. 1—5. 



Habitat. — C. Crag, S. W. {Recent) Britain, N. E. Bean, King ; Coast of Norway, 

 M"- Andrew ; Arctic Sea, >S'. E. Belcher. 



Owing to its being apparently wholly a northern form, the occurrence of R. Beaniana 

 among the Crag fossils is of much interest. The principal characters by which it is distin- 

 guished from R. cellulosa, consist in the existence, in front of the orifice, of a prominent 

 rostrum crowned with an avicularium, and of an oral spine at each upper angle. Of these 

 characters, those which longest remain distinct in the older portions of a polyzoariura, are 



