54 



GUIDE TO THE CORAL GALLERY. 



Case 2 c, d. Stylaster sanguineus, or the " Blood Coral " from the Pacific 



Islands, is of a brilliant red colour. 



In Astylus (Fig. 18) the cyclo-systems all face one way. Crijpto- 

 helia pudica is remarkable for the little canopy which arches over 

 each cyclo-system. 



Disticho}wra has the pores arranged in a triple row along each 

 edge of the flattened branches, a central row of gastropores being 

 enclosed between two parallel rows of dactylopores. Probably the 

 various supposed species of Distkliopora (D. cocdnea, violacea, livida) 

 are colour variations of one species. 



Fig. ifj.' 



Enlarged view of the surface of a living Millepora, showing five dactylopore 

 polyps surrounding a central gastropore polyp. (After Moseley.) 



III. MEDUSA AND OTHER ALLIED FREE-SWIMMING 

 CCELENTERA. 



Case 3, Glass models of Medusae or Sea-Nettles are exhibited in 



par . ^j^^ upright part of Case 3 along with specimens in spirit. Medusae 



have already been referred to in the account of Hydroida and 



of Millepora, where it was stated that in some species certain 



polyps carrying the eggs (generative polyps) became detached 



' From "Encyclopaedia Britannica." 



