MADREPOEA. 173 



occur at intervalsj some of which form twigs, others remain short and nipple-shaped ; 

 sometimes quite half the corallites on one surface of a branch bear buds, at others very few. 

 Star well developed, the two directive septa very broad. Corallum dense; surface and wall 

 densely echinulate, not striate, though striato-echinulate when thin. 



Pacific Ocean : Torres Straits and Great- Barrier Reef area. 



a-g. North Australia. J. R. Elsey, Esq. [P.]. 57. 11. 18. 204, 209, 214, 



to 218. (Types.) 

 h-l. Thursday Island. Saville-Kent Coll. 92. 6. 8. 241-245. 



m. North Australia. Saville-Kent Coll. 92. 6. 8. 246. 



n. Rocky Island. Saville-Kent Coll. 92. 6. 8. 247. 



8. Subgenus EHABDOCYATHUS. 



Axial corallites stout, cylindrical, the free portion not usually longer than broad ; wall 

 thick and dense ; margin more or less rounded ; star usually 12-rayed. The more prominent 

 radial corallites are also thick- walled and are usually provided with more than six septa; 

 they sometimes also resemble the axial ones in form. The habit is either bushy, fruticose, or 

 flattened and reticulate, with branchlets on the upper surface only. There is sometimes an 

 approach to the bottle-brush form in the arrangement of the twigs, but in such cases, so far 

 as known, the twigs are always longer on one side of a branch than on the other. 



A. Corallum bushy, fruticose or subarborescent. Radial corallites of the same form as the 

 axial ones, and some of them are scarcely smaller in diameter. 



187. Madrepora hemprichi. 



Ueteropora hempricJdi, Ehrenberg, Corallenth. d. roth. Meeres, p. 109. 



Madrepora forsJcalii (part.), M.-Edwards & Haime (non Ehrenberg), CoraUiaires, t. ill. p. 151. 



Madrepora hemprichii, Klunzinger, Korallenth. d. roth. Meeres, Th. ii. p. 6, pi. i. fig. 2, pi. iv. fig. 17, 



pi. ix. fig. 1; Ortmann, Zool. JB. 1888, Bd. iii. p. 149; ibid. 1889, Bd. iv. p. 503 (non 



Haeckel, Arab. KoraUen, pi. ii. fig. 6). 

 Madrepora obtueata, Klunzinger, Korallenth. d. roth. Meeres, Th. iL p. 7, pi. i. fig. 5, pi. iv. fig. 18, 



pi. viii. fig. 20, pi. ix. fig. 2 ; Ortmann, Zool. JB. 1888, Bd. iii. p. 149. 

 Madrepora variolosa, Klunzinger, Korallenth. d. roth. Meeres, Th. ii. p. 8, pi. i. tig. 6, pi. iv. fig. 16, 



pi. ix. fig. 3. 

 1 Madrepora rudis, Rehberg, Abhand. nat. Ver. Hamburg, 1892, Bd. xii. p. 41, pi. iv. fig. 9. 



Corallum laxly arborescent or bushy, erect or oblique, with or without occasional 

 fusions, 15 to 20 cm. high, or more in the case of slender arborescent forms. Branches 

 usually about 1 cm. thick, sometimes elongate and little divided, at others shorter and much 

 branched, tapering somewhat towards the apex. Axial corallites 4 to 5 mm. broad, 3 to 



2 A 



