Key to the species Chalarostylis

1. Carapace, pereonites and pleonites all with long setae................................................. C. guanchi

- Carapace with setae on anterior third, or none............................................................... 2

2. Dorsal crest serrated........................................................................... C. elegans

- Dorsal crest smooth or entire........................................................................... 3

3. Antenna accessory flagellum longer than first two articles of main flagellum............................. C. canadensis

- Antenna accessory flagellum shorter than first two articles of main flagellum...................................... 4

4. Uropod peduncle with 9 setae medially; antennule accessory flagellum shorter than first article of main flagellum.................................................................................................... C. longisetae

- Uropod peduncle with more than 10 setae medially; antennule accessory flagellum equal or longer than first article of main fla- gellum.............................................................................................. 5

5. Antennule accessory flagellum equal to or barely longer than first article of main flagellum................... C. bruunae

- Antennule accessory flagellum nearly reaching end of second article of main flagellum...................... C. brenkei .