Nowrarcturus, Poore, 2013

Poore, Gary C. B., 2013, Rectarcturidae Poore, 2001 rediagnosed with descriptions of new Australian genera and species (Isopoda: Valvifera), Memoirs of Museum Victoria 70, pp. 17-36 : 21

Nowrarcturus gen. nov.

Zoobank LSID. http://zoobank.org/ urn:lsid:zoobank.org:act:

6D11DFB5-917A-4D1C-8F2A-AAC9969DD029

Type species. Nowrarcturus jamesi sp. nov., by monotypy and original designation.

Diagnosis. Head with paired submedian tubercles, pereonites with smooth transverse ridges (third with second ridge anterior to major one), anterior pleonites barely elevated. Antenna 2.5 times dorsal length of (head + pereonite 1); article 3 cylindrical, twice as long as deep, without ventrolateral flange; article 4 cylindrical, more than twice as long as fused articles (1 + 2); article 5 cylindrical, 1.5 times as long as article 4, 5 times as long as wide. Pereopod 2 propodus palm convex, denticulate; (dactylus body + unguis) 2.5 times as long as propodus; unguis setiform, little longer than dactylus body. Pereopod 3 similar to pereopod 2, unguis shorter. Male pleopod 1 exopod groove ending obliquely on conical apical projection, extending beyond distomesial seta-bearing lamina. Male pleopod 1 endopod about three-quarters exopod length. Oostegites 5 a pair of adjacent oval discs.

Etymology. From Nowra, a town in NSW near to the type locality of the type species, and Arcturus , generic stem.

Composition. Type species only.

Distribution. Southern NSW, Australia.

Remarks. The sole species of Nowrarcturus is distinguished by smooth transverse ridges on pereonites 1–4 and the elongate articles of the antennal peduncle. The relationship between the two lobes of the major transverse ridge on pereonite 3 and the pair of smaller lobes opposing it anteriorly, especially evident in females, is unique. This genus is the only rectarcturid in which the groove on the exopod of the male pleopod 1 ends obliquely on a conical apical projection, extending beyond the distomesial seta-bearing lamina.