110 CORALS AND CORAL ISLANDS. 
The corals of colder waters, either outside of the coral-reet 
seas, or at considerable depths within them, comprise, accord- 
ingly, the following :— 
1. A very few Fungids. 
2. Some of the Oculinids; many of the Astrangids and 
Caryophyllids; a few Stylophorids. 
3. Many of the Eupsammids. 
4. Some of the Gorgonia and Pennatula tribes, and a few 
of the Aleyonium tribe. 
5. Milleporids of the genus Pliobothrus; many Stylasterids. 
A large proportion of the cold water species are solitary 
polyps. 
Through the torrid region, in the central and western Pa- 
cific, that is, within 15° to 18° of the equator, where the tem- 
perature of the surface is never below 74°F. for any month of 
the year, all the prominent genera of reef-forming species are 
abundantly represented—those of the Astraacea, Fungacea, 
Oculinacea, Madreporacea, Aleyonoids, Millepores and Nulli- 
pores. The Feejee seas afford magnificent exainples of these 
torrid region productions. Astras and Meandrinas grow 
there in their fullest perfection; Madrepores add flowering 
shrubbery of many kinds, besides large vases and spreading 
folia; some of these folia over six feet in expanse. Musse 
and related species produce clumps of larger flowers ; Meru- 
line, Echinopore, Gemmipore and Montipore form groups 
of gracefully infolded or spreading leaves; Pavoniz, Pocilli- 
pore, Seriatopore and Porites branching tufts of a great vari- 
ety of forms; Tubipores and Xenie, beds or masses of the 
most delicately-tinted pinks; Sponggodiz, large pendant clus- 
ters of orange and crimson; and Fungie display their broad 
disks in the spaces among the other kinds. Many of the 
species may be gathered from the shallow pools about the reefs. 
