302 Mr. H. J. Carter on 
pliocena; but subsequent and more particular examination 
shows that it has several specific differences, viz. :—1, the visi- 
ble venation is much denser in H. Kingii than in H. pliocena ; 
2, there are no spines on the former, which, as before stated, 
are represented by pustuliform elevations; 3, the entire mass 
is irregular in form and extended into a thick lobo-branch or 
process here and there; 4, the vertical tubes present no dia- 
phragm or septal divisions, except the one above mentioned. 
It has been named after Prof. King, of Galway, who kindly 
sent me the specimen, which he thought came from the Sub- 
apennines and had already received a name. 
Millepora alcicornis. 
As this is a well-known species, having been named by 
Linneus, stated by Ellis and Solander to be so abundant 
in the West Indies as to be ‘used principally for burning 
into lime,” and pronounced by Agassiz, in 1859, to be “ very 
nearly related to the Hydractiniz,” I shall only describe so 
much of it (from a dried fragment which, by accident, has 
lately fallen into my hands with fragments of sponges which 
indicate that it came from the seas between the two Americas) 
as may be necessary for the purpose of showing how closely 
allied in structure its corallum or polypary is to that of Stroma- 
topora. 
Its specific designation well indicates the general form. — 
The surface is harsh to the touch from being composed of the 
pointed free ends of a meandering reticulation of anastomo- 
sing more or less flat fibre, whose interstices form the openings 
ot a subjacent structure, which will be more particularly de- 
scribed hereafter, rendered uniformly uneven or bossed by 
gentle elevations and depressions ; over which, scattered more 
or less irregularly, are many apertures that may be divided 
into two sets, viz. large and small, the latter most numerous ; 
the largest, which more especially have a toothed or sub- 
asteroid margin, are about 1-120th inch in diameter and 
1-12th inch. apart, while the smaller ones are about 1-225th 
inch in diameter and 1-48th inch apart; but both vary 
slightly in size and in their distances from each other. Be- 
sides this, the surface presents here and there an intricate 
tubular venation composed of chitinous canals in relief, more 
or less covered with calcareous material, whose minute branches 
anastomose freely over the points of the meandering reticu- 
lation mentioned, and, in many instances, become lost beneath 
it, the largest branches averaging 1-360th inch in diameter. I 
note this particularly because we shall find remnants of it 
by-and-by (fig. 8, @) on the surface of the fossil called 
