Diagnosis (female). Body stout, consisting of distinct cephalosome and extremely inflated trunk. Rostrum with rounded apex. Abdomen extremely reduced to short lobe; caudal rami absent. Antennule 3- to 7-segmented; first segment bearing 2 setae. Antenna 3-segmented, with armature formula 1, 4, and 5 or 6. Labrum distinct. Mandible consisting of coxa with well-developed gnathobase and palp with 1 to 3 distal setae, or palp represented by seta. Maxillule consisting of precoxa and palp; precoxa with 6 or 7 spiniform setae on arthrite; palp unsegmented with 4 or 5 setae. Maxilla consisting of syncoxa with 1 large endite tipped with 2 elements, and allobasis with 4 or 5 elements. Maxilliped unsegmented, unarmed or armed with 4 setae. Legs 1-4 biramous with 2-segmented exopods; endopods 1-segmented in Buprçrus and 2-segmented in Buprçrẚdes gen. nov.; coxa unarmed; basis of leg 1 with or without inner distal element. Leg 5 unsegmented, extending beyond posterior margin of abdomen and armed distally with several setae.
Remarks. The family Buproridae was established by Thorell (1859) to accommodate his new monotypic genus, Buprçrus Thorell, 1859. However, in their comprehensive revision of the family Ascidicolidae, Illg & Dudley (1980) accorded this taxon subfamily status, as the Buprorinae. They considered that the antenna of all the other subfamilies within the ascidicolid series could be derived from a limb exhibiting the basic structure of the antenna in Buprçrus (Illg & Dudley, 1980). Marchenkov & Boxshall (2002) compared the antennal segmentation patterns across all subfamilies of Ascidicolidae and showed that the ancestral first and second endopodal segments of the antenna are fused in Buprçrus and the third endopodal segment is free, and that the main flexure plane of the limb lies between the basis and endopod. In contrast, in all of the other subfamilies the third endopodal segment is fused with the second and the main flexure plane of the limb lies between the ancestral first and second endopodal segments. Based primarily on this difference, Marchenkov & Boxshall (2002) treated the Buproridae as a family level taxon.
Until the present account, the Buproridae remained a monotypic family represented only by the genus Buprçrus. The genus Buprçrus currently consists of three species: B. lçvenẚ Thorell, 1859 known from Scandinavian waters and from off Mauritania in the eastern North Atlantic (Thorell, 1859; Marchenkov & Boxshall, 2002) and from the Atlantic coast of America in the western North Atlantic (Dudley & Illg, 1991), B. nçrdgaardẚ G.O. Sars, 1921 known from Norway (Sars, 1921), and B. caudatus Illg & Dudley, 1980 known from southern California on the Pacific coast of America (Illg & Dudley, 1980).