Ctenophora
. Comb Jellies , a phylum of about 100 widely distributed marine animals resembling jellyfish. The comb jellies have eight rows of comblike plates arranged longitudinally around the body. The plates are moved back and forth in a rippling motion and serve to propel the animal through the water. Most species have two long tentacles at either side of the transparent body, which are used to capture prey. In general the bodies of comb jellies are oval, with a throat opening into the body cavity. They have no separate digestive system, the particles of food being ingested by the individual cells within the body. A sense organ at the opposite end of the body from the mouth is composed of a mass of tiny bony particles, supported away from the body on four legs. Impulses from this organ pass through the legs and into the body of the animal along grooves in the body that contain a large number of hairlike cilia. These grooves, although not true nerves, perform a similar function. Most of the cte