PORITES FROM NO RECORDED LOCALITY. 117 



Other branching forms are known in which the superficial calicles are quite obscure in 

 the surface texture. One striking example is P. Great Barrier Rmf 12, see Vol. V. p. 118. 



Some notice ought here to be taken of a coral which has caused a great deal of confusion. 

 I refer to the small encrusting Porites from no certain locality belonging to the Berlin Museum, 

 and called by Ehrenberg P. punctata. This was seen by Milne-Edwards and Haime, and made 

 into a new genus Stylarcea Miilleri, but later these same authors changed it back to Ehrenberg's 

 original name. Dr. Khmzinger recognised it, as well as Ehrenberg's Porites arenacea, as being 

 tlie same as certain forms which he had found in the Red Sea. Passing over all the con- 

 fusions of names we have the simple facts just related ; see the remarks in Vol. V. p. 243. 



111. Porites x. 9. (Porites incertm sedis nona.) (PI. VII. fig. 1.) 

 [British Museum.] 



T/escription. — The coral! um forms small, thin, encrusting patches which follow theuneven- 

 ness of the substratum. The margin, sometimes free, is about " 5 mm. tliick, closely supported 

 by an epitheca. 



The calicles are ill-defined as faint depressions in an otherwise smooth, soft-looking 

 surface. Their radial symmetry is only seen by looking vertically downwards into the 

 narrow interseptal loculi. They are 1 mm. in diameter. The walls are quite flat without 

 median ridges, and consist of so much reticulate tissue deeply and irregularly incised by 

 the interseptal loculi which sometimes communicate with those of adjoining calicles. 



The septa are tliick, with granulated or finely echinulated sides, and regularly meet and 

 fuse in four pairs and one triplet in the typical manner. The apices of these triangular groups 

 of septa reach nearly to the centre and are slightly enlarged as pali, which as such are not 

 distinguishable. An iiregular columellar tubercle fills up the minute fossa. 



There are two small colonies of this Porites, one about 3 • 5 to 4 cm. across, and the other 

 about 1 cm. The larger one is on the stem of a Mussa, while the smaller lurks between its 

 calicles. 



The absence in this Porites of any clearly defined wall, the long interseptal loculi, the 

 obscurity of the pali, and the presence of the minute tuliercle filling up tlie fossa, give this coral a 

 resemblance to a Psammocora. But close observation shows (1) tliat there are frequently small 

 areas of delicate mural reticulum between the calicular areas as marked by the septa ; (2) that 

 the septa meet and fuse in the typical manner for Porites, no such fusion being known in Psam- 

 mocora. The fact that Dr. Klunzinger made the same comparison for his Porites echinulata, see 

 P. Bed Sea 7, Vol. V. p. 241, which also grew on the branches of older corals, suggested the 

 possibility of this being specifically identical, but Dr. Klunzinger's photograph shows an 

 entirely dilferent calicular structure. 



There is unfortunately no recorded locality, nor do the characters either of the Porites 

 itself or of the immense Mussa which it encrusts give us any clue to its home. 



a. Two small patches on a Mussa. Zool. Dept. 1900. 1. 1. 14. 



