DEEP-SEA AMPHIPODA FROM THE WESTERN NORTH ATLANTIC OCEAN: I. INGOLFIELLIDEA AND AN UNUSUAL NEW SPECIES IN THE GAMMARIDEAN FAMILY PARDALISCIDAE

Ingolfiella atlantisi n. sp. is described from a depth of 4892–4743 m in. the North American Basin, the first ingolfiellid amphipod known from this basin and only the second known from the deep sea. It is a member of a characteristic deep abyssal group of amphipods. The distribution and ecology of the 13 known species in the genus Ingolfiella are summarized. Present evidence is insufficient to distinguish a relic distribution of the known members of this genus from a cosmopolitan distribution of many species. The description of I. atlantisi illustrates the dangers of early splitting of lit tie-known groups into several genera.The pardaliscid amphipod Eperopeus abyssicola n. sp. is described from several locations at abyssal depths in the range 2500–4977 m. It shows a striking convergence to members of the genus Ingolfiella, especially in general body form but also in partial reduction of the coxal plates and partial reduction of the pleopods. This is the second example of such a convergence in the gammaridean amphipods.