DESCRIPTION OF CHALK CORALS. 243 
present of discussion ; but should such agreements be detected, still they would 
not make the fossils immediately under examination Turbinolia, as those species 
would not structurally accord with T. crispa and T. sulcata, which are invariably 
admitted to be generic types. 
For single, fixed corals wanting the central structure of Cyathina, Ehrenberg 
proposed the term Monomyces with the following characters :—lamellz simple ; 
mantle non-retractile, enveloping the exterior to the root ; stems fixed, solitary 
or with simple germs on the side, not branched :—the genus being considered 
equivalent to fixed Fungie and single Caryophyllia (op. cit. p.77). Three species 
are noticed. The first, Mon. patella or Fungia patellaris of Lamarck, is a free 
coral as exhibited by Ellis and Solander'’, and is stated by them to be ‘‘ acaulis.”’ 
39 
Lamarck says, ‘‘elle a quelquefois un pedicule court en dessous?:” two of 
Ksper’s figures®, referred to by that authority, exhibit something like a foot- 
stalk, but the apparent structure is alluded to in the description as a portion of 
some unknown coral‘ ; two other figures however (6 & 7) display a bold, cylindri- 
cal body protruding from the centre of the under side; it is, nevertheless, not 
affirmed to be a part of the specimen. Whatever may be the nature of that 
zoophyte, all pediculated Fungie are most probably, if small, young examples of 
amature free state®, or if large, abnormal developments. The second species, Mon. 
Anthophyllum, is believed to be unfigured ; the description also is not full, and 
Mr. Dana refers it to Euphyllia (op. cit. p.160. Flabellum of Lesson). ‘The third 
species assigned doubtfully to the genus is the Fungus eburneus of Shaw®, but it 
would appear from his delineation to be closely allied to Mon. Anthophyllum. 
The chalk fossil having been considered by some authorities a single Caryophyllia, 
and exhibiting evidently mature conditions of growth, would seemingly belong to 
Ehrenberg’s genus; but one of the leading characters of Monomyces is a perfectly 
enclosing non-retractile mantle, whereas the extinct coral was enveloped to only 
a certain extent, and not always to the same amount. Moreover no account is 
given of the internal composition ; and provided Mr. Dana’s conclusion is correct, 
transverse plates between the lamellz do not exist, being absent in Flabellum 
pavonium, and it is presumed in analogous Huphyllie. Monomyces consequently 
‘ Natural History of Zoophytes, or Lamouroux, Exp. Méthodiq. tab. 28. figs. 1-4, p. 52. 
> Anim. s. Verteb., 2nd edit. t. ii. p. 372. no. 4. * Pflanzenthiere, Madrep. tab. 62. f. 1, 2. 
* Op. cit. Fortsetzungen, Erster Theil, pp. 76, 77. 
° Consult Mr. Stutehbury’s Memoir, Trans. Linnean Soe. vol. xvi. p. 493 et seq. pl. 32. 
® Travels in Barbary, &c., 3rd edit. vol. ii. plate at p. 369. fig. 18. descrip. p. 371. no. 18. 
