32 MADREPORARIA. 
UNION ISLANDS. 
4. Porites Union Islands ql. (P. Tokelauensis prima.) 
[Duke of York Island ; Hamburg Museum.] 
Syn. Porites cylindrica Rehberg (? Dana), Abh. Naturwiss. Ver. Hamburg, xii. (1892) p. 47. 
Dr. Rehberg merely recorded the existence of a perfectly preserved branching Porites in 
the Hamburg Museum from this locality. He compared it with both Dana’s “cylindrica” 
(? Fiji Islands) and with Briiggemann’s “decipiens” from Ponapé. It should be noticed that the 
latter author did not himself suggest any affinity between his coral and Dana’s. 
SAMOA. 
5. Porites Samoa qy]l. (P. Samoensis prima.) (Pl. I. fig. 6; Pl. XIII. fig. 2.) 
[Samoa, coll. Count Castelli; British Museum.] 
Description.—The corallum is a single, complete, detached, nearly cylindrical stem 6 cm. 
long and 2-5 c.m. thick, with base partly encircled by an epithecal film, Small nipple-shaped 
processes, 1 cm. long by 0°5 cm. thick, grow out irregularly from what was the upper surface of 
the sloping stem, and tend to form a cluster at its tip. 
The calicles are very minute, 0°5 mm., quite superficial. The details of skeletal structure 
are obscured by surface granules, but the walls appear to be flaky, and, as compared with the small 
size of the calicles, thick (0°3 mm.), The walls rise as an irregular ring of round very frosted 
granules. These encircle an inner ring of septal granules; within this again is a compact 
regular ring of slightly larger pali. From the pali we gather that the septal formula is typical, 
as can indeed be occasionally seen. The fossa is minute, usually deep, but here and there 
closed by a central tubercle below the level of the pali. The interseptal loculi, when visible, 
show the radial symmetry of the calicles, and sometimes run from the fossa on to the walls. 
There are three variations in the texture of the surface: (1) the calicles are clearly visible, 
because the flakes and granules are small, and show traces even of septa with deep intervening 
interseptal loculi; (2) the calicles are obscured owing to the prominence, large size, and con- 
sequent crowding of the frosted granules, making the whole surface an elegant mosaic, but at 
