150 CTENOPHOBA 



Family 2. FUNGIIDAE. (Mushroom Coral.) 



Coral solitary or colonial, often of large size, flat and disc-like in shape 

 with numerous septa; the living disc covers the septa and from its surface 

 rise very numerous tentacles ; the embryo gives rise to a conical coral called 

 a trophozooid, the upper part of which expands, breaks off, and becomes 

 the adult coral, a process which may repeat itself a number of times; 

 about 12 genera. 



FxTNGlA Dana. Coral solitary and of large size, convex on the 

 upper and concave on the lower side; without siphonoglyph : numerous 

 species, 1 American. 



F. elegans Verrill. Coral round and thick, about 6 cm. in diameter: 

 Gulf of California. 



SuBPHYLUM 3. CTENOPHOEA.* 



Very soft and delicate jellyfishes which live mostly in the surface 

 waters of the sea. The body is usually more or less spherical, pear-shaped 

 or cylindrical in shape, and is both radially and bilaterally symmetrical. 

 Its outer surface is without hard skeletal structures and bears eight 

 longitudinal bands of cilia, which are the characteristic "combs" 

 (Fig. 249) and the organs of locomotion. Each of these bands is com- 

 posed of a series of transverse plates formed by the fusion of long cilia. 

 The animal has an oral and an aboral end which are opposite each other. 

 At the former is the mouth, an elongated slit which leads into a deep 

 flattened cavity lined with ectoderm, called the stomach. It is into this 

 space that the food is taken and digested. At the aboral end of the 

 body is a slight cavity which is connected with the eight bands of cilia 

 by four ciliated grooves, and in which are calcareous concretions and 

 sensory cells. The sense organ thus formed is called the statocyst and 

 is an organ of equilibration. 



Many ctenophores have a pair of long retractile tentacles which 

 project from a pair of deep pockets in opposite sides of the body (Fig. 

 249). These tentacles have short branches or pinnae and their ectoderm 

 is provided with numerous peculiar adhesive cells which aid in cap- 

 turing and killing the prey; they are very retractile, and can be wholly 

 or partially withdrawn into the pockets. Other tentacles and projec- 

 tions are also present in certain species. 



• See "Ctenophorae," by L. Agassiz, Contributions to the Natural History of 

 the United States, Vol. 3, p. 155, 1860. "Die Ctenophoren des Golfes v. Neapel," 

 by C. Chun, Fauna u. Flora d. Golfes v. Neapel, Vol. 4, 1880. "The Ctenophores of the 

 San Diego Region," by 11. B. Torrey, Univ. of Cal. Pub., Vol. 2, p. 45, 1904. "Cteno- 

 phores of the Atlantic Coast of North America," by A. G. Mayer, 1911. 



