Bovallius, 1887
Length to 18 mm (females), to 9 mm (males). In females (Phronima colletti 1), pleon and urosoma (including UR) combined 0.96±0.03 times as long as head and pleon combined; pleonite I 0.81±0.03 times as long as pereonite VII. ART 4 of P V slightly longer than wide, posterior margin rounded (Phronima colletti 3); ART 5 moderately narrow, carpal tubercle low, with 3-4 tooth-like projections and separate anterior tooth, carpal process moderate, bent slightly backward; ART 6 subequal to palmar margin of ART 5. Rami subequal in all UR, or exopodite slightly longer than endopodite in UR II.
In males (Phronima colletti 2), pleon and urosoma (including UR) combined 1.13±0.07 times as long as head and pleon combined; pleonite I 0.94±0.07 times as long as pereonite VII. ANT II well-developed, half as long as, or longer than, ANT I, flagellum 12-17 articulated. ART 5 of P V similar to, but wider than, that of female (Phronima colletti 4); ART 6 subequal to palmar margin of ART 5. Rami subequal in all UR, or exopodite slightly longer than endopodite in UR II.