80 PERCY SLADEN TRUST EXPEDITION 



1857. Favia geoffroyi, MUne Edwards and Haime, Hist. Nat. Corall., ii, p. 433 = Parastrea geoffroyi, Valen- 

 ciennes, Mss., Catal. Mus. Paris. 



1857. Favia deformata, Milne Edwards and Hainie, Hist. Nat. Corall., ii, p. 434. 



1857. Favia savignyi, Milne Edwards and Haime, Hist. Nat. Coral]., ii, p. 437. 



1857. Favia aspera, Milne Edwards and Haime, Hist. Nat. Corall., ii, p. 438 = Parastrea aspera, Valenciennes, 

 Mss., Catal. Mus. Paris. 



1 1857. Prionastraa seychellensis, Milne Edwards and Haime, Hist. Nat. Corall., ii, p. 517. 



1857. Prionastrcea halicora (pars), Milne Edwards and Haime, Hist. Nat. Corall., ii, p. 517. 



1879. Favia denticulata, Klunzinger, Korall. Roth. Meer., ii, p. 27. 



1879. Favia clouei, JKlunzinger, Korall. Roth. Meer., iii, p. 29 (non Favia clouei, Milne Edwards and Haime). 



1879. Favia ehrenbergi, Klnnzmger, Korall. Roth. Meer., iii, p. 29, pi. 3, fig. 5 (var. laticollis), ?fig. 7 (gowcilin- 

 lichste Form), fig. 8 (var. sulcata), and pi. 9, figs. 1,, and Ij. 



? 1879. Goniastrma seychellensis, Klunzinger, Korall. Roth. Meer., iii, p. 33, pi. 4, fig. 3. 



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



1 1'j04. Favia versipora, Gardiner, Fauna Geogr. Maldive and Laccadive ArchipeL, ii, p. 766. 



1904. Prionastrcea spinosa, Gardiner, Fauna Geogr. Maldives and Laccadives, p. 785. 



1904. Prionastrcea magnistellata, Gardiner, Fauna Geogr, Maldives and Laccadives, p. 788, pi. 64, figs. 40 

 and 41. 



1904. Prionastrcea suvadivce, Gardiner, Fauna Geogr. Maldives and Laccadives, p. 789. 



1906. Favia savignyi, Marenzeller, Exp. " Pola," Rot. Meer, Riffkorall., Zool. Ergeb. Wien, xxvi, p. 56, pi. 25, 



f]gs. 84 — 89, and pi. 24, fig. 79 (= Madrepora cavernosa, Forskal). 



1907. Favia savignyi, Vaughan, Proc. U.S. Nat. Mus. Washington, xxxii, p. 256. 



Corallum. Massive, often rounded, sometimes incrusting. Corallites polygonal, 

 often distorted, sometimes oval, slightly projecting, with distinct rims, up to 5 mm. 

 apart, the intervening perithecal regions being flat and vesicular. Calices varying 

 much in size, up to 20x12 mm., average 12x10 mm., somewhat decreasing in width 

 from calicular margins to bases, by depth up to 14mm, average 8 mm. 



Septa usually thin, sometimes thickened, vertical or slightly sloping with toothed 

 edges, rough sides, 60 — 70 in number in the largest coralhtes, 30 — 45 in the average 

 sized ones; up to 25 septa meeting columella (usually about 18), about 1 or l"25mm. 

 exsert, with up to 14 teeth, usually becoming elongated from calicular margin to 

 columella. A definite pali-crown absent. Some of the broader subsidiary septa usually 

 curving towards and fusing with sides of principals. Exsert ends of septa arched or flat, 

 finely toothed, meeting in notches or not actually meeting, giving an appearance of furrows 

 over the perithecal regions, sometimes directly continuous from corallite to corallite. 

 Columella varying in degree of development, from loosely inter-crossing septal teeth 

 to twisted trabeculee. 



Multiplication by fission, more often sub-equal than unequal. 



The skeleton is highly variable in this species but two main types are to be recog- 

 nized : (l) characterised by light corallum, somewhat narrow perithecal regions, large 

 and deep calices, numerous thin septa, the principals with their lower halves or one-thirds 

 somewhat oblique, columella imperfectly formed {e.g. Prionastr(Ba inagnistellata, Gard., 

 Favia jacquinoti, Ed. and H., Favia geoffroyi, Ed. and H.) ; (2) a thicker and rougher 

 type with heavy corallum, broader perithecal regions, smaller and shallower calices, 

 fewer septa but broader at the calicular margins, thicker and rougher, the principals 

 dipping vertically to the columella or their lower parts usually entire, broader, ending 



