Identification key for Western Atlantic species of Cyamon
(Details of spicule set see Fig. 5 and Table 1 and 2)
1a. Two categories of styles...................................................................... C. arguinense
1b. Three or more categories of styles........................................................................ 2
2a. Polyactines I spined and II smooth, both of usual shape (cladi diverging from a single central point).................... 3
2b. Polyactines I of usual shape and polyactines II unusual (spined cladi diverging at two lateral points at both ends, called amphipolyactines)..................................................................... C. amphipolyactinum
3a. Megascleres are only styles in three categories (I, III and IV)............................................ C. agnani
3b. Megascleres are styles in five categories and strongyles in two categories................ Cyamon pedroalcoladoi sp. nov.