Stegocephalexia penelope Moore, 1992

Vader, Berge Wim, 2001, North Paci ® c species of the amphipod (Crustacea) family Stegocephalidae, with description of one new species and redescription of another, Journal of Natural History 35, pp. 985-1000 : 989

Stegocephalexia penelope Moore, 1992

( Figure 1, d±g)

Stegocephalexia penelope Moore, 1992: 928 .

Material examined. PARATYPES: Female 4.5 mm, Cat. NMCC1990-0364 , 52 ss 00 ¾ N, 128 ss 30 ¾ W, 45 m, 18 November 1975 ; Immature 2.5 mm, Cat. NMCC1990-0365 , 52 ss 00 ¾ N, 128 ss 30 ¾ W, 45 m, 18 November 1975 .

Distribution. [271] known only from its type locality in British Colombia (see above).

Short description to supplement Moore’s (1992) original description: antenna 1 ¯agellum ®ve-articulate; accessory ¯agellum uni-articulate. Epistome convex, unproduced, epistomal plate absent. Labrum with lobes asymmetrical, left lobe strongly reduced. Maxilla 1 outer plate ST in a 7 / 2 pseudocrown: ST 1±5 present, ST 6 absent, ST 7 present, ST A present, relocated and part of ®rst row, ST B absent, ST C present; inner plate with setae pappopectinate. Maxilla 2 inner plate with row A, B and C present, row A and B both marginal and appressed together. Maxilliped palp article 2 distally weakly produced; outer plate outer setae row present, marginal, setae straight and attached in a deep hollow, inner row present but strongly reduced, submarginal, distally weakly transverse, distal setae group present, long simple setae attached in a deep hollow, inner plate with two nodular setae, medial setae-row present but reduced to two pectinate setae, distal row present, reduced to one seta, inner row reduced to one long robust seta. Males with propodus enlarged on pereopod 2.

Remarks. The present species was described by Moore (1992) in the new monotypic genus Stegocephalexia , based mainly on the unhooked setae on the outer plate of the second maxilla and on the broad and rounded basis on pereopod 6. However, examination of the type material has revealed that the morphology of the maxilliped, together with an enlarged male propodus on pereopod 2, resembles that of Stegocephaloides Sars, 1895 , but that both maxilla 2 and pereopod 6 resemble that of both Stegocephalus hancocki Hurley, 1956 and Phippsiella pajarella Barnard, 1967 . Thus, the phylogenetic relationships of this species is highly uncertain. Pending a revision and cladistic analysis of the entire family (Berge et al., in press), its relationships with the other stegocephalid species are left without any further discussion.