Ithyomus, Bird, Graham, 2004

Bird, Graham, 2004, Tanaidacea (Crustacea) of the Northeast Atlantic: non­filiform species of Anarthruridae Lang from the Atlantic Margin, Zootaxa 471, pp. 1-44 : 17

Ithyomus gen. nov.

Anarthrura: Bird, 2001: 27 .

Type Species. Ithyomus conopygus sp. nov., by monotypy.

Diagnosis. Anarthrurid with well­developed pleon. Labrum conical, not laterally compressed. Mandible without molar (?) Maxillule endite with seven terminal spiniform setae. Maxilliped palp article­3 with three long inner setae; endite with one long seta. Cheliped propodus without lateral fold; fixed finger with two ventral setae. Pereopod 1–3 coxa with seta. Pereopod 4–6 merus, carpus and propodus with spiniform setae with complex tips, carpus with four of these. Pleopod exopod with setae on entire ventral and distal margin. Uropod exopod with three setae.

Etymology. From Greek ithys, meaning ‘straight’ and omos ‘upper arm’, alluding to the pseudocoxa­basis articulation.

Remarks. As with most diagnoses defining new monotypic genera it is provisional and will be tested if and when very similar species are recorded elsewhere. The combination of four spiniform pereopod carpal setae, three palp setae (article­3) and no cheliped propodal fold is unique.