Key to the species of Harpilius Dana, 1852

1. Dactylar segment of second maxilliped forming long narrow strip along medial edge of propod; with postorbital ridge; R 7­8/2­3 ........................ Harpilius lutescens Dana

­ Dactylar segment of second maxilliped not forming long narrow strip along medial edge of propod............................................................................................................... 2

2. Rostrum less slender, straighter, well exceeding scaphocerite; R.8/1­2 ......................... .................................................................................... Harpilius consobrinus De Man

­ Rostrum more slender, distally up­curved, scarcely exceeding scaphocerite; R. 7­8/3­5 ........................................................................................... Harpilius bayeri (Holthuis)