EL-ARISH

Egyptian city on the Mediterranean, on the Wadi el-Arish, and chief city of the territory bearing the same name. It was taken by the French under Kléber in 1799, but abandoned the same year. Pop. about 20,000. scales (dermal denticles) are embedded in the skin. The skeletun is cartilaginous; the heart po e es a muscular conus arteriosus with numerous rows of pocket valves; and there are five (sometimes six or seven) pairs of gill-pouches opening by slits to the exterior, these not being covered by an external flap 92 ELASMOTHERIUM (operculum) except in chimeroids. Fertilization is internal, and the male is provided with a pair of copulatory organs (claspers) projecting backwards from the pelvic fins. The eggs sometimes develop within the body of the mother, but are usually laid in horny pouches (mermaids’ purses). The group is of great antiquity, and many extinct fo il types are known.