FAMILIES AND GENEEA OF THE MABEEPOEAEIA. 145 



III. Alliance HERPOLITHOIDA. 



Colonial Fungidse, with some or all tke calices incomplete and not 

 radiating. 



Genus Herpolitha, Eschholtz. 

 Genus PoLYPHYLLiA, Quoy. 

 Genus Lithactinia, Lesson. 

 Genus Zoopilus, Dana. 



Grenus Heepolitha, JEschJioltz, Isis, p. 746 (1825), amended; 

 Duncan, Jburn. Linn. Soc, Zool. vol. xvii. p. 152 (1883). 



The corallum is free, long, narrow, and compound. The upper 

 surface lias calices of two kinds — one set occupy a long central 

 axial line and are multilamellar, and the other set are placed irre- 

 gularly, have few lamellge, and are small. The septo-costal rays 

 are long and stout, and alternately tliick and thin, and all are 

 entire. ISTo rays reach from the axial furrow to the circumference. 

 The base is concave, perforated and echinulated. Synapticula 

 regular, numerous, oblique, tall, and wanting here and there. 

 Columella trabecular. 



Distribution. — Becent. Eed Sea, Indian Ocean to east. 



This genus has been called HerjpolitTiios by Leuckart subsequent 

 to Eschholtz (see Hist. Nat. des Corall., Milne-Edwards & Jules 

 Haime, vol. iii. p. 24) ; and Xlunzinger has restored the proper 

 name (' Korallenthiere des Eotlien Meeres,' p. 68). 



Genus Polyphtllia, Quoy et Gaimard, Voy. de V Astrolabe 

 (Zooph.), p. 185, pi. 20 (1833); Dana, Encplor. Exped., ZoopTi. 

 p. 316 (1846). 



Corallum compound, free, oblong, and convex above and con- 

 cave below, or discoid. Calices incomplete ; sonae, which are sub- 

 radiant, occupy the central axis in the long coralla, and are asso- 

 ciated with rudimentary calices placed on either side, with short 

 septo-costal rays very unequal in size, separated by trausverse 

 laminae, which are the prolongations of a lower set of septa. Or 

 the surface is covered with undeveloped calices with uon-radiant 

 septo-costse. The base is echinulate and perforate. S;^napticula 

 well developed. Principal septa very thick. 



Distribution. — Becent. Pacific, Eed Sea. 



There are no perfectly radiating calices in the genus Poly- 

 phyllia — that is to say, the centre of a calice has not septa radia- 

 ting from it, as in Halomitra for instance. The radiation is 



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