102 PERCY SLADEN TRUST EXPEDITION 



exocoelic pleats for a short distance from the stomodseal attachment. Mesenterial endo- 

 derm quite thin and of more or less uniform thickness along the entire width of the 

 mesentery. Convolutions of the mesenteries abundant below the stomodseum to the 

 base of the polyp, being massed in the inter-mesenteric chambers. Filaments are found 

 on all the mesenteries. In the larger polyp ova present, in up to five rows in every 

 mesentery, with the endoderm granular and swollen on either side of them. 



Number of polyps examined, two, from a specimen from Hulule, Maldives. 



Remarks. Milne Edwards and Haime placed Astrea dipsacea, Audouin (Expl. 

 Savignyi, Descr. I'Egypte, xiii. p. 57, pi. 5, fig. 3, 1809), under Favia savignyi, Ed. and 

 H. I have not been able to see this example. If Klunzinger is correct in identifying it 

 with Acanthastrcea hirsuta, then the present species would be named F. dipsacea. 



Of the five specimens now in the Berlin Museum referred by Ehrenberg to Astrea 

 dipsacea, only one (later re-named Acanthastrcea hirsuta var. megalostoma by Klunzinger) 

 comes under the present species. Klunzinger's figured example of var. Tnegalostoma is not 

 in the Berlin Museum. 



Milne Edwards and Haime named 7 specimens (3 large, one with the microstoma 

 facies, and 4 small, all from Red Sea) Acanthastrcea hirsuta, Ed. and H., 4 speci- 

 mens (2 large and 2 small, from unknown locality) Acanthastrcea brevis, Ed. and H., 

 and 4 large specimens (3 from Bed Sea and 1 from unknown locality) Acanthastrcea 

 grandis, Ed. and H. ; I could not find any differences separating these three species. 

 They also named two very small specimens from Tongatabou Acanthastrcea spinosa, Ed. 

 and H., these doubtless also belonging to the present species. Lamarck's original of 

 Acanthastrcea dipsacea is similar to the megalostoma examples. A specimen from Red 

 Sea named Cceloria hottce, Ed. and H., also comes under the present species. Quelch's 

 type of his new species, Acanthastrcea irregularis, is a small, thin, convex specimen from 

 Kandavu, Fiji, measuring 7 x 7'5 cm., in no way difierent from the hirsuta examples. 



Localities. Maldives, Hulule (l). Red Sea (1). lEUice Islands, Funafuti (a frag- 

 ment). Also from Tongatabou (Milne Edwards and Haime), Fiji (Quelch). 



11. Favia acropora (Linnaeus). (PL 25, figs. 1 and 3 ; 26, fig. 4 ; 33, fig. 1.) 



1767. Madrepora acropora, Linnaeus, Syst. Nat., edit. 12, p. 1276.' 



1788. Madrepora acropora, Gmelin, Linn. Syst. Nat., edit. 13, p. 3767. 



1797. Madrepora acropora, Esper, Forts. Pflanz., p. 21, pi. 38, figs. 1 and 2. 



1815. Favia acropora, Oken, Lehrb. Naturg., i, p. 68. 



1816. Astrea pleiades, Lamarck, Hist. Anim. sans vert., ii, p. 261 ; 2^ ^dit., p. 408 (non Madrepora pleiades, 



Ellis and Solander). 



1850. Astrea pleiades, Milne Edwards and Haime, Ann. Sci. Nat., Zool., 3" s^r., xii, p. 105. 



1850. Parastrea lobata, Milne Edwards and Haime, Ann. Sci. Nat., Zool., 3'^ ser., xii, p. 171. 



1857. Favia lohata, Milne Edwards and Haime, Hist. Nat. Oorall., ii, p. 434, pi. D8, fig, 3. 



1857. Heliastroea acropora, Milne Edwards and Haime, Hist. Nat. Oorall., ii, p. 477. 



1879. Favia lohata, Klunzinger, Korall. Roth. Meer., ii, p. 31, pi. 3, fig. 9, pi. 10, fig. 8. 



1899. Astrcea lohata, Gardiner, Proc. Zool. Soc. London, p. 749. 



1899. Orhicella acropora (pars), Gardiner, Proc. Zool. Soc. London, p. 752. 



1899. Orhicella orion, Gardiner, Proc. Zool. Soc. London, p. 752. 



1906. Orhicella lobata, Marenzeller. Exp. "Pola." Roth. Meer., Riffkorall., Zool. Ergeb. Wien xxvi, p. 61. 



Corallum. Massive, rising into hillocks, which usually decrease in thickness from 



their summits. Peritheca vesicular or compact. Corallites circular, dividing ones 



