Length 10-17 mm (Paraphronima gracilis 1, males to 11 mm). Head very large and robust in comparison with slender delicate body and thin P, longer than pereonites I-IV combined, more than twice as high as pereonites. Pereonites I and II clearly smaller than pereonite III. ART 4 of P I with spoon-like process in posterodistal part, P II simple, with narrow linear ART, P III-VI subequal. P VII shorter than P VI (reaching distal end of ART 5 of P VI). Rami of all UR shorter than basipodites. Live animals glass-like, transparent, with two rows of red facets in eyes, small subsurface glitter dots near base of each P; dots glow golden-orange in light.