454 
COSLEI^T^llATA. 
Luminosity. . The Penuatulidce are provided with special luminous organs 
in the shape of 8 strings, attached to the external surface of the stomach, 
commonly in its whole length (in Cavernularia obesa only the upper extremity 
appears to be developed). The luminous power is restricted to these organs, 
which occur not only in the polypes, but also in the “ zooids,” and contain 
cells of the usual yellowish fatty granular matter, discovered by Panceri 
(11) in all other instances of phosphorescence. 
Geographical Distribution, Local Lists, Coral Reefs. Gray, Ann. N. H. (4) 
X. pp. 124 & 125, has published a list of Corals &c. collected by Andrew 
in the Red Sea. Verrill, Am. J. Sc. (3) iii. pp. 432-437, enumerates 14 
species of Anthozoa from North Carolina, and mentions some others in his 
paper “On the Distribution of Marine Animals on the Southern Coast of New 
England,” Ann. N. II. (4) ix. pp. 92-97. Grube, Abh. schl. Ges, 18C8-09, 
p. 128, and 1809-72, pp. 143 & 144, enumerates the species observed on the 
west coast of France j while Fischer and Folin, C. R. Ixxiv. pp. 760-753, 
briefly allude to those found on dredging oft‘ Cape Breton, from 24 to 
250 fathoms j Whiteaves, Ann. N. H. (4) x. pp. 345 & 346, to those found 
in the Gulf of St. Lawrence, and Greeep (Madeira &c. p. 31) to those ob- 
served at the Canaries. Semper (14) describes the Turbinolidce, Eupsam- 
miidce, &c. of the Philippines. In the last chapter of his work on the Pen- 
natididce, Kolliker (6) gives a tabular view of the geographical and bathy- 
metrical distribution of the 120 known species of Sea-pens, and slates the 
general results us to the distribution of the genera, tribes, &c. 
Dana’s work (1) discusses the subject more from a geological than a 
zoological point of view j but the connexion between these is so intimate that 
some notice of it must be here made. The observations forming the basis of 
the work were made on the cruise of the Wilkes Exploring Expedition of 
1838-42, during which many of the coral islands of the Paumotu archipelago 
and the Society, Navigator, and Friendly Islands, the Fiji group, several 
islands north of the Navigator and Fiji groups, including the Gilbert or 
Kingsmill group, the Sooloo Sea, and Singapore (all reef regions) were exr 
plorod. The first chapter gives a sketch of corals and coral-makers, not only 
of the Actinarian and Alcyonarian orders, but also of Ilydrozoa {Millepora) 
Po/yzo«,‘and calcigerous algae (^Nullipora^ ) the distribution in latitude and 
depth of reef-building corals, the local causes influencing their gi’owth and 
distribution, their rate of growth, &c. are elaborately discussed. The second 
chapter describes the general features, special characters, and structure of 
coral reefs (considered under distinct headings as “ outer reefs,” fringing 
reefs and shore reefs with no barrier reefs to protect them, and inner reefs ”) 
and “coral islands ” (atolls), with detailed accounts of a number of islands, 
the Florida reefs, and the Bermudas. The third explains the formation of 
reefs, the causes modifying their form, and their rate of growth the theory 
of barrier reefs and atolls is explained (Darwin’s explanation of the problems 
connected with them being accepted) j and vivid descriptions of the completed 
atolls terminate this chapter. The fourth treats of the geographical distri- 
bution of coral reefs and islands, and leads naturally to a discussion of the sub- 
sidence and elevation in the Pacific. A concluding chapter gives the 
geological results of this study of the coral formations with regard to the 
formation of limestone, absence of fossils in such strata, formation of dolo- 
mite, &c. 
