760 ME. J. STA^'LEY GARDIJv'ER OX [Juue G, 



3. Pbionastb^a purpurea Dana. 



Astnea purpurea, Dana, Zooph. p. 239, pi. xii. fig. 10 (1848). 



Frionastrcea puiyurea, Milue-Edwards & Haime, Cor. ii. p. 524 

 (1857). 



Dana states that this species differs from P. pentagona (Ehren- 

 berg) onl3''by the absence of a corona of teeth round the columella 

 and the presence of a sulcus on the tops of the walls. Some 

 of the calices of one of my two specimens show a corona of broad 

 teeth round the columella and the sulcus is not always present. 

 I have, however, retained Dana's name, as Ehrenberg's description 

 is useless without reference to the original specimens, which are 

 unknown. 



The polyps and coralliun agree absolutely with Dana's description 

 and figures, except fig. 10 b of the septa. There are generally 

 present 40-50 septa, of which about half are much thicker than 

 the rest and fuse -with the columella. The edges of these latter 

 septa end usually in 6-9 fine rectangular teeth, often 1 mm. oi- 

 more in length, and have rather a ragged appearance. The large 

 septa are continuous between the calices with thin walls, but the 

 sulcus is always marked by a deep notch immediately over the 

 centre of the wall. The columella is always very well developed, 

 usually oval in shape, about 3 mm. by 2 mm. It is generally 

 situated about 2 mm. below the edges of the septa, and in surface 

 view appears to be almost a solid mass, but is really composed of 

 extremely fine and closely anastomosing trabeculae. 



Eotuma ; reef with the preceding species. Two specimens. 



P. gibbosa of Klunzinger appears to come very close in its 

 characters to this species and is almost certainly identical with it. 

 One of my dried specimens is rather gibbous, but this is not a 

 specific character. 



4. PbionastRjEa hirsuta Milne-Edwards & Haime. 



AcantJiastrcea hirsuta, Milne-Edwards & Haime, Ann. des Sc. 

 Nat. ser. 3, xii. p. 145 (1850), and Cor. ii. p. 502, pi. D 5. fig. 4 

 (1857). 



AcantJiastrcea hirsuta, Klunzinger, Die Korall. des E. Meeres, 

 iii. pi. v. figs. 1-2 (1879). 



I have referred a small colony with 19 calices to this S])ecies, 

 with which it agrees absolutely in all the characters given by 

 Milne-Edwards and Haime. Budding takes place within the 

 calices, and also very markedly over the costte at the edge of the 

 colony. 



Eunafuti. 



5. Prionastb^a echinata Dana. (Plate XLVII. fig. 6.) 

 Astrcea echinata, Dana, Zooph. p. 229, pi. xii. fig. 1 (1848). 



I have referred a single specimen (about which 1 have no notes 

 as to colour) to this species, with which it agrees absolutely in all 

 the described and figured characters. There are about 30 septa, 



