308 Dr. F. Briiggemaim on Stony Corals. 



species from St. Domingo {A. Lonsdaleia, Duncan, Quart. 

 Journ. Geol. Soc. xx. p. 30, pi. iii. fig. 4), from which iti 

 stated to differ onlj in its general shape. 



2. AntilUa explanata. 



Afitillia explanata, Pourtales, 111. Cat. Mus. Comp. Zool. Cambr. viii. 

 p. 42, pi. viii. figs. 4-6. 



Hab. Barbadoes, in 75 fathoms depth. 



3. AntilUa Geoffroyi. B.M. 



TurbinoUa Geoffroyi, Audouin, Descr. Egypt. Expl. Planch, p. 233 (ex 



Savignv, op. cit. Polypes, pi. 4. fig. I) ; Cana, U.S. Expl. Exped. Zooph. 



p. 190,'note. 

 Trachi/phylUa Geoff royi, M.-Edw. & Hainie, Ann. Sc. Nat. (3) xi. 



p. 276 ; iid. Hist. Nat. Cor. ii. p. 341 ; Hackel, Arab. Korall. p. 45, 



pi. ii. fig. 2. 



Hah. Red Sea; Gulf of Suez (i?. MacAndreio in B.M.). 



This coral is exceedingly variable. The calicle is rounded 

 in the youngest specimens, afterwards it becomes either broad 

 explanate (and then the coral is always very short) or com- 

 pressed, even linear, much more so than in the species of 

 Flabellum. The proportion between the shorter and longer 

 axis varies, in middle-sized specimens, from 1:2 to 1:5. 

 When the calicle is open it is generally irregularly constricted 

 in its sides, and there are indications of paliform lobes, although 

 these are never much pronounced ; in tlie compressed speci- 

 mens they are, of course, wanting. 



The present species has been regarded by the French 

 monographists as the young of a compound coral allied to 

 TrachyphylUa amarantum. This is a mistake : the young 

 Ti-achyphyUire, of which thei^e are several examples in the 

 Museum collection, begin to divide at a very early period, and 

 exhibit the same in-egular plications as the adult ; they have 

 also no trace of an epitheca. On the contrary, all the nume- 

 rous specimens of A. Geoffroyi before me are quite simple, 

 without any inclination to divide ; the animals (preserved in 

 spirit) show constantly a single mouth, however elongate 

 the calicle may be ; the epitlieca is always present and neatly 

 defined, although less extensive in the young. 



Savigny's and Milne-Edwards's specimens Avere evidently 

 not " very young," but fully adult, and, to judgefrom their enor- 

 mous size, probably very aged. The only mode of asexual 

 propagation J have noticed in this species is that by means of 

 intracalicular budding ; in one specimen this has repeatedly 

 taken place, "and thus three calicles are placed one in the 

 other, not unlike the fossil Cyathophyllum. 



