Neonesidea keyseri Brandão, 2008

LV and RV subtrapezoidal, posterior angle acute, valve surface smooth, with very numerous and long sensilla. LV with rounded dorsal, anterior and posterior margins, and straight ventral margin. RV with more angulated outline than LV, with straight anterodorsal and ventral margins. Inner lamella narrow, vestibules constricted. Radial pore canals simple and with rim. Adductor muscle scars arranged in 3 horizontal rows, dorsal row with 2 scars, middle and ventral rows with 3 scars each. In dorsal view, carapace lozengeshaped with acute anterior and posterior angles, maximum width anterior to mid-length.

Antennula with very long, distal setae, segment VII very elongate. Antenna elongate, especially segment IV and V; exopodite with 1 long and 2 very short setae; segment VI with 1 long, distally spatulate claw, 1 short seta, and 1 short, fused seta, all simple. Mandibula and maxillula with several feathered setae and claws. Base of mandibula with 1 anterodorsal seta, masticatory process with 1 dorsal bifurcate, 4 medial trifurcate, and 1 ventral bifurcate teeth, plus several short setae. Palp of maxillula with one ventral, long seta, 3 dorsal, medium-sized setae, and 2 distal, medium-sized setae, one of the distal setae modified, cylindrical, with feathered tip; vibratory plate with 2 strahlen and about 21 feathered setae. Vibratory plate of fifth limb with 3 strahlen and 10 feathered setae. Long claws of segment V of ApV to VII distally spatulate. Furca with 5 short setae and 2 medium-sized, distal setae.