SUB-CLASS I ANTHOZOA—TETRACORALLA 79 
between which and the theca vesicular endotheca is abundantly developed. 
Common in Carboniferous rocks. 
Strombodes, Schweigg. Astraeiform stocks composed of small prismatic 
corallites. Septa extremely numerous, very slender, extending to the centre. 
Theca imperfectly developed. Visceral chamber filled with infundibuliform 
tabulae and vesicular tissue. Silurian (S. typus, M‘Coy sp.) and Devonian. 
Pachyphyllum, Spongophyllum, E. and H. Silurian and Devonian. 
Acervularia, Schweigg. Astraeiform or bushy colonies. Septa stout and 
numerous. An interior wall is present; tabulae are developed in the central 
area, while the peripheral zone is filled with vesicular tissue. Silurian (4. 
ananas, Lin. sp.) and Devonian. 
Phillipsastraea, E. and H. (Fig. 123).  Astraeiform colonies, with indi- 
vidual corallites united by confluent septa, which are produced beyond the 
theca, and obscure the same. Interseptal loculi filled with vesicular endotheca. 
Devonian and Carboniferous. 
Stawia, KE. and H. (Fig. 124). Astraeiform or bushy composite coralla. 
Septa well developed ; the four principal septa characterised by larger size, and 
forming a complete cross in centre of each corallite. Silurian (Wenlock). 
Columnaria, Goldt. (Favistella, Hall).  Astraeiform stocks, composed of 
long, polygonal, thick-walled corallites. Septa radially arranged in two cycles, 
alternately long and short, barely reaching the centre. Tabulae horizontal, 
disposed at regular intervals apart, and stretching across the entire visceral 
chamber. Dissepiments imperfectly developed or absent. Ordovician to 
Devonian. 
Heterophyllia, M‘Coy. Carboniferous.  Battersbyia, E. and H. Devonian. 
Family 5. Cystiphyllidae. Milne-Edwards and Haime. 
Usually simple coralla. Septa very thin ; interseptal loculi filled with vesicular 
endotheca or compact stereoplasma. Tabulae absent ; central 
area of visceral chamber either completely filled with vesicular 
tissue or stereoplasmua, or contuining the same only in the 
lower portions of chamber. Culcareous operculum sometimes 
present. 
Cystiphyllum, Lonsd. (Figs. 125, 126). Simple, very 
rarely forming bushy colonies. Calice deep; the entire 
visceral chamber filled with vesicular tissue, which, as a 
rule, wholly obliterates the numerous lineally directed 
septa. Silurian and Devonian. 
Strephodes, M‘Coy (Fig. 127). Usually simple coralla. 
Septa well developed, alternately long and short, some- 
times forming a pseudo-columella. Silurian to Carbon- 
iferous. 
Gomophyllum, E. and H. (Fig. 128). Corallum simple, 
in the form of a four-sided pyramid, and covered with 
thick epithecal deposit. Calice deep; septa numerous, 
thick and very short. Entire visceral chamber filled with — cystipnyziun — vesiewlosum, 
vesicular and stereoplasmic endotheca. Operculum com- Qoll! | Devonian 1, Eifel 
posed of four plates symmetrically paired. Silurian. 
Lhizophyllum, Lindst.  Corallum simple, pyramidal, or hemispherical, 

Fic. 125. 
