SUB-CLASS II HEXACORALLA—A POROSA—ASTRAEIDAE 85 
Family 4. Stylophoridae. Milne-Edwards and Haime. 
Composite coralla, with corallites united by vesicular or compact coenenchyma. 
Septu well developed, forming a central 
columella ; interseptal loculi empty 
throughout. Jurassic to Recent. 
Stylophora, Schweig. (Fig. 138). 
Stock branching, or depressed, 
massive, and tuberous. Calices small, 
embedded in abundant, at the surface Sia 
spinous, coenenchyma. Septa_ well nae 
developed, moderately HMA OLS Stylophora subreticulata, Reuss. Miocene; Grund, near 
columella styliform. Jurassic, Ter- iene a, Corallum, natural size; b, Surface greatly 
tiary, and Recent. Pap 
Araeacis, KE. and H. Eocene. Stylohelia, E. and H. Jurassic and Cretaceous. 

Family 5. Astraeidae. Milne-Edwards and Haime. 
Corallum composite, or more rarely simple. Theca formed by fusion of septal 
edges. Septa numerous, usually well developed ; visceral chamber partitioned off by 
more or less abundantly developed dissepiments, more rarely by tabulae. Multiplication 
by budding or fission. Corallites of massive colonies usually reaching considerable 
altitude, and united with one another either directly by the walls or by means of septa 
exothecally produced (costal septa). 
Very abundant from the Trias onwards, and by far the most protean family 
of all the Heaacoralla. According to the serrated or entire character of the 
free septal edges, Milne-Edwards divides the Astraeidae into two sub-families— 
the Astraecinae and the Husmilinae. 
Sub-Family A. Astrarrnagk. Milne-Edwards and Haime. 
Upper septal edges toothed, serrated, or lobular. 
a. Simple coralla. 
Montlivaultia, Lamx. (Fig. 139).' Cylindrical, conical, turbinate, or dis- 
coidal, and either acutely pointed, or broadly expanded at the base. Septa 

Fig. 139. Fic. 140. 
Montlivaultia caryophyllata, Lamx. sp. Great Leptophyllia sinuosa, From.  Neocomian ; 
Oolite ; Caen, Calvados. Natural size. St. Dizier, Haut-Marne. Natural size. 
numerous, upper edges serrated. Columella absent ; epitheca thick, corrugated, 
readily becoming detached. Common in Triassic and Jurassic ; somewhat rare 
in Cretaceous and Tertiary. 
Leptophyllia, Reuss (Fig. 140). Like the preceding, but without epitheca, 
and attached by broad base. Jurassic and Cretaceous. 
