218 DE. G. J. hi:nde on septaste^a, d'oebignt (1849), 



In the minute structui^e of the septa and the formation of the 

 theca by the extension of the septal laminae, Septastrcea still further 

 differs from Favia, Goniastrcea, and their allied forms ; and pending 

 a more complete rearrangement of the Aporose Corals it may pro- 

 visionally be taken as the type of a new subfamily, the Septastraeinae. 



Septaste^a Poebesi, E. & H. (PL IX. figs. 1-5, 7-15, 17.) 



1849. Septastrcea Forhesi, E. & H. Ann. des Sci. Kat., 3^ se'r. 

 t. xii. p. 164. 



1849. Septastrcea siibramosa, d'Orbigny (nominal), Note sur les 

 Polypiers fossiles, p. 9. 



1852. Septastrcea suhramosa, d'Orbigny, Prodr. de Pal. vol. iii. 

 p. 146. 



] 857. Septastrcea Forhesi, E. & H. Hist. nat. des Corall. vol. ii. 

 p. 450. 



1861. Septastrcea Forhesi, de Promentel, Introduction, &c. p. 174. 



1864. Septastroea Forhesi, Meek, Check-list Invertebr. foss. N. 

 American Miocene, p. 1. 



1886. GlypTiastrcea Forhesi, Duncan, Abstract Proc. Geol. Soc. 

 London, no. 495, p. 18. 



1887. Glypjliastrcea Forhesi, Duncan, Quart. Journ. Geol. Soc. 

 vol. sliii. p. 29, pL 3. 



CoraUum of large flattened masses with lobate or digitiform ex- 

 tensions, or of rounded or compressed stems with short rounded 

 branches. Mode of attachment unknown. Entire surface of coral- 

 lum covered with calicos in close contact. In normal corallites 12 

 septa developed, but frequently only six extend to centre of corallite. 

 The septa of the third cycle only indicated by slight vertical ridges. 

 In abnormal corallites the number of the septa may be reduced to 

 2, 4, or 5, or increased to 16 and even to 36. The fully mature 

 calices are shallow, from 1 to 3 millim. in depth, polygonal, with 

 thickened margins, an impressed line or linear rows of tubercles 

 marking the division between individual calices; the upper surface 

 of the wall and the septal upper edge likewise covered with tubercles, 

 but the surfaces of the septa in the interior of the corallites are 

 smooth. Ploor of ealice in mature corallites entirely closed, the 

 upper edges of the septa slightly projecting above the floor, which 

 has a dome-shaped elevation in the centre. In calices not mature 

 the walls are thin, the floor is incomplete near the periphery, but 

 usually filled up in the central portion to a varying extent. 



Dissepiments very thin, irregularly developed, occasionally at the 

 same level in the different interloculi, usually from 1 to 2 millim. 

 apart, the uppermost dissepiment forming the base to the infilling 

 of solid stereoplasm. No indications of a genuine columella. Presh 

 buds formed at the interspaces between the walls of adjoining mature 

 corallites : no instances of real fission present. 



The largest specimen (incomplete) is 160 millim. in height, 120 

 in width, and from 20 to 50 millim. in thickness. The corallites vary 

 from 4 to 6 millim. in diameter, their average width is 4-5 millim. ; 



