MILLEPORE, a genus of hydrozoa which have recently been placed in a new sub class, hydrocerallina3 by Mr. Moseley. It contributes largely to the formation of coral reefs in the West Indies and Pacific. The calcareous skeleton is mostly in the form of laminar expansions having the surface studded with minute holes of two sizes, the large,r being the fewest. The larger openings are the mouths of tubes which are divided by transverse calcareous partitions into a number of compartments, only the most super ficial of which contain the animals. The smaller tubes are similarly constructed, and the general tissue of the skeleton is composed of trabeculre traversed by a series of anastomosing canals which place the tubes occupied by the zooids in direct communica tion. On account of some resemblance in the skeleton the millepora were formerly classed with the labulate corals. The late Prof. Agassiz was the first to examine the living animals, and he at once referred the genus to the hydrozoa. Mr. Moseley arrived at
the same conclusion, and has recently had opportunities of examining the living animal minutely. According to him the co:ony of millepores consist of two kinds of zobids. The larger, or gastrozooids occupy the larger tubes of the skeleton, while the smaller, or dactylozooids occupy the smaller tubes, which are generally placed around the larger in somewhat of a systematic arrangement. The small, or dac 841 h ty.ozo........s _Jive 110 mouth and are long and slender, carrying on their sides numerous short, clavate teataeles. They pet-form the functious of prehension for the colony, and supply food to the stomach bearing gastrozoiiids, which perform the work of digestion and tmimilation for the family. The nutritive fluid thus elaborated is diStributed to the colony through branched canals which ramify in every direction. The reproductive process is still unknown. See INVERTEBRATE ANIMALS.