UNKNOWN ATLANTIC OR WEST INDIAN PORITES. 85 



70. Porites West Indies %. 5, (P. Americana incertm scdis quinta.) (PI. XIII. fig. 5.) 

 [" Les Mers d'Am(5rique," " coll. Lamarck " ; Paris Museum.] 



Description. — The corallum forms erect, rather stiff clusters of flattened stems, which fuse 

 edge to edge to form flabellate plates, showing lines of fusion. As each component stem forks 

 into two sharp teeth, the uppermost edge of the plate runs out into a row of short tapering 

 points, like the teeth of a saw. The tips of these are 4 mm. thick, the stems 1 ■ 5 cm. The 

 living layer is 7 cm. deep. 



The calicles increase from 0'75 mm. at the top, where they are deep, to 1'25 mm. at the 

 base, where they are shallow. They are funnel-shaped, angular, very variable in shape, as regular 

 polygons, or drawn out into slits. The wall has a sharp, median ridge, as a clear white line. 

 In older, more regular calicles, the septa are very irregular, being short, tliick, and wedge-shaped, 

 with here and there a half-separated granule at their tips. These stray granules are apparently 

 the only representatives of the usual palic formula. In smaller and younger calicles the 

 radial symmetry is quite obscured, and the walls of the calicles are encrusted on their inner 

 sides with granules, which slope down round a deep, open, sometimes very large fossa. 



This desci'iption is that of a specimen in the Paris Museum (No. Z 187 h) ; it is labelled 

 " P. furcata, coll. Lamarck ; Mers d'Am(''rique." This coral and the last are interesting, because 

 if named by Lamarck at all, they show that he had a different interpretation of the word 

 furcata from that which has been recently adopted by authors who have written upon the 

 West Indian Porites. The latter, by furcata, have meant rather more open branching; 

 Lamarck meant more like a fork with sharp prongs. 



The condition of the calicles is remarkable ; the depth of the fossa, witli the absence of 

 pali, are noteworthy characters which, though rare, are not unknown in the genus ; we have it 

 normally in the astrseoid group and occasionally in some of the Indo-Pacific forms. 



This Porites ought to be easy to identify again. Although in view of the doubt as to the 

 authenticity of the record on the label, the locality " Mers d'Amerique " is, in this coral, also 

 open to suspicion. (See the observation under the last heading.) 



PI. XVI. fig. 4 represents another coral in the Paris Museum (No. Z 187 «(), with an 

 exactly similar record on the label. It again differs from any yet descriljed. 



71. Porites West Indies x. 6. {P. Americana incertce sedis sexta.) 



[This is the specimen preserved in the Berlin Museum and recorded as from the Red Sea, and 

 named Poiites clavaria Ehrenherg, Corallenthiere des Rothen Meeres (1834) p. 117 ; 



and renamed Porites nodifera Klunzinger, Korallthiere des Rothen Meeres, ii. (1879) p. 41, pi. v. 

 fig. 17, pi. vi. fig. 13.] 



This coral has already been described in Vol. V. p. 239. I was aware, at the time, of the 

 suggestion that the record of the locality might have been accidentally changed, and that the 



