Stebbing, 1888
Body often with dorsal spines and carina (especially on pleon), sometimes smooth. Pleon well-developed. Rostrum variable, large, or absent. ANT I longer or shorter than ANT II, accessory flagellum absent or uni-articulate, scale-like or elongate, sometimes fused with ART 3 of peduncle. Accessory flagellum of ANT I in eusirids, when present, often poorly visible, requiring high magnification. ANT often with numerous calceoli in both sexes. Coxae medium-large or small. MD with 3-articulated palp, molar usually triturative, sometimes reduced or simple. Lower lip with or without inner lobes. Shape of P I and II often distinctive: strongly subchelate, ART 5 very narrow, bag-like ART 6 attached to very narrow margin, and thus ART 6 strongly flexible relative to axis of ART 5; palm opposite articulation of ART 5 and 6; ART 5 with narrow outgrowth in middle of posterior margin (so-called "eusirid gnathopod", see Eusirus perdentatus 1, Eusirus properdentatus 2). P I and II normal in other cases, strongly or weakly subchelate; in former case, ART 6 often enlarged and broadened, lanceolate or elongate-oval, with palmar margin almost equal to posterior margin of ART, ART 5 with more or less well-developed posterior lobe. P V-VII often elongate. Exopodites of UR I and II usually shorter than endopodites. Telson cleft or entire (in the calliopiids). Sixty five genera, mainly benthic. Seven genera in plankton of South Atlantic.
Genera treated:
Genus Cleonardo Stebbing, 1888
Genus Eusirella Chevreux, 1908
Genus Eusiroides Stebbing, 1888
Genus Eusiropsis Stebbing, 1897
Genus Eusirus Krøyer, 1845
Genus Harcledo Barnard, 1964
Genus Rhachotropis Smith, 1883
Genus Stenopleura Stebbing, 1888