POLYNESIAN PORITES. 99 
SANDWICH ISLANDS. 
81, Porites Sandwich Islands (91. (P. Hawatensis prima.) 
[Sandwich Islands, coll. Wilkes Expedition, 1838-42 ; 2 ] 
Syn. Porites mordaz Dana, Zooph. (1848) p. 552, pl. liii. figs. 3, 3a. 
P. mordaz var. elongata, ibid. fig. 4. 
Description—The corallum forms open clusters of stout, nearly erect branches. The 
clusters may be 25 cm. across and 20 cm. high. The branches are slightly compressed, under 
1 cm. thick and from 1 to 2°5 cm. broad, fused at the bases into stout plates or cavernous 
masses, but free for from 4 to 5cm. The living layer extends downwards 9 to 10 cm. The 
cluster thickens as it rises. Some specimens are massive and sub-lamellar, with obtuse lobes 
above instead of branches. 
The calicles are large, 1°5 mm. deep and funnel-shaped; the walls are thin, sharp, and 
granular; the septa are sharp, thin, scabrous; the columellar tangle and tubercle are distinct. 
There is a somewhat inconspicuous ring of pali. 
Judging from Dana’s text and figures, from which the above is compiled, there can be 
little doubt that the calicles are very like those of some of the other Sandwich Islands Porites 
which are in the Museum, e.g. Nos. 5 and 6. They all have a certain roughness of texture. 
In this case the roughness seems to have been increased by an upgrowth of the wall-reticulum 
in the angles, such as is seen to some extent in No. 6, only there the young calicles develop in 
these upgrowths. This is the interpretation which I put upon Dana’s description. There is, 
however, a specimen in the Paris Museum (No. Z, 192a) labelled P. mordaxz, Sandwich Islands, 
showing the walls raised into sharp ridges, somewhat like the ccenenchymatous ridges in 
P. Society Islands 2, the P. latistellata of Quelch from Tahiti. If this specimen is correctly 
identified, Dana’s words “angles prominent” should have been “wall ridges prominent.” 
Dana’s figure of an enlarged calicle hardly leads one to expect such a specialisation, and there 
are no other specimens in the British Museum from the Sandwich Islands showing such ridge 
formation. 
Dana’s variety elongata ought, perhaps, to have been described separately. There is 
evidently a close resemblance between the calicles of all the Sandwich Island forms, This 
may be another instance of the similarity in surface characters of corals coming from the 
same waters, often noticed before in this Catalogue. However, as it is the growth-forms 
which mainly distinguish these Sandwich Islands Porites, Dana’s elongata, with its long, 
tapering, moniliform stems, might well have been described separately. 
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