8 INVERTEBRATE ANIMALS. 



Division PERFORATA. Rays well developed : coral 

 porous. 



Group 20.— Family PORITID^. Reef-building corals, 

 usually massive. Estimated number of species : recent, 

 83 ; British, ; fossil, 36. 



U Examples of Psammocora, Montipora, Alveopora, 

 and other genera. 



Group 21.— Sub-family TURBINARIN^ (Milne Edwards). 

 Turbo, a top. 



Genus TURBINARIA (Oken) = GEMMIPORA 

 (Blainville). Estimated number of species: recent, 

 11 ; British, ; fossil, 7. 



II Large foliaceous and cup-shaped Corals from the 

 East Indies and the Fiji Islands. Dome- 

 shaped specimen of Astraopora, remarkable for 

 its highly finished calices. 



Group 22.— Genus MADREPORA (Linn^us). Part I. 

 The name is from the Italian, signifying Mother-pore, 

 the apical polype being the parent of the rest on the 

 same branchlet. Natives of tropical seas : one species 

 is known from the White Sea. 



Upper Compartment. 

 Larger Corals, including M. palmata, an explanate 

 Madrepore, sometimes attaining a height and 

 breadth of seven feet. 



Group 23.— Genus MADREPORA (Linn^us). Part IL 

 Estimated number of species in genus Madrepora ; 

 recent, 84 ; British, ; fossil, 6 ; Kainozoic. 



IT M. ecJmiata, M. carduus, M. longicyathus, 

 and other slenderly branched Madrepores, are 

 amongst the most beautiful of all the coral tribe. 



