TRIBE I. ASTR^ACEA. 203 



The mode of budding separates the Astraeae from the Caryophyllia 

 and Cyathophyllum families. Yet in some massive species the distinc- 

 tion is not readily observed, especially between the Astrseas and cer- 

 tain Cyathophylla, which agree in the general character of the cells. 

 When treating of the Cyathophyllidae, the distinguishing character- 

 istics will be more particularly dwelt upon. The lamello-striate 

 surface of the Astrsese will afford an almost invariable character for 

 distinguishing them from the recent species of the Caryophyllia tribe ; 

 and adding to this the many transverse dissepiments between the 

 lamellae, which are remote, if at all existing in the latter, and there 

 will be little chance for confounding them. The Astraeae, however, 

 graduate into the Caryophyllia) through the small Orbicellce, the A. 

 ocellina and A. myriophthalma, closely resembling Oculinee, and 

 hardly distinguishable, except by their glomerate or incrusting forms 

 and general habit. (See farther under Oculina.) The same transition 

 also takes place through the A. pleiades and the Astroites. These 

 last species exhibit their Caryophyllia character, however, in the fact 

 that the aggregated polyps are united only by the lower parts of the 

 animals, as is evinced by their becoming long exsert when expanded : 

 moreover, we perceive in their coralla that the new cells open in the 

 interstices, although but a fraction of a line in breadth ; while all 

 Astraeas, with similarly narrow interstices, bud in the disks. They 

 are thus similar to the Porites among the Madreporacea. 



The genus Astraa was so named by Lamarck, in allusion to the 

 stellate cells, and was instituted with nearly the same limits as here 

 adopted.* The Astrceoporce were separated from it by Blainville, and 

 the A. palifera was arranged by the same author with his genus 

 Gemmipora; and these changes have been here adopted. A few 

 other species, having the stars of the Pavoniss, have been placed in 

 this work with that genus : these are in part the Siderastraeae of 

 Blainville, and are characterized by the absence of proper cells, and 

 the lamellae being uninterruptedly continuous between the polyp 

 centres or oririmes. 



* Astrcea, the goddess Justice in ancient mythology, " lived upon the earth, as the 

 poets mention, during the golden age, which is often called the age of Astrsea ; but the 

 wickedness and impiety of mankind, drove her to heaven in the brazen and iron ages, 

 and she was placed among the constellations of the Zodiac under the name of Virgo." 



" Virgo csede madentes 



Ultima crelestum terras Astreea rcliquit." Ovid, Met. i. 150. 



