Pseudocallisoma, Horton, Tammy & Thurston, Michael H., 2015

Horton, Tammy & Thurston, Michael H., 2015, A revision of the genus Paracallisoma Chevreux, 1903 (Crustacea: Amphipoda: Scopelocheiridae: Paracallisominae) with a redescription of the type species of the genus Paracallisoma and the description of two new genera and two new species from the Atlantic Ocean, Zootaxa 3995 (1), pp. 91-132 : 122

Pseudocallisoma gen. nov.

Paracallisoma— Dahl, 1959: 220.— Gurjanova 1962: 308.— Hurley 1963: 60.— Barnard 1964: 319, 1969: 305.— Barnard & Karaman 1991: 510.

Type species. Scopelocheirus coecus Holmes, 1908 , by original designation.

Diagnosis. Mandible, left lacinia mobilis a stemmed, distally asymmetrically expanded non-serrate blade; incisor ordinary; molar simple, small, subconical; palp attached slightly proximal to molar. Maxilla 1 inner plate strongly setose medially; palp 2-articulate, large. Maxilla 2 inner plate broader than outer, inner and outer plates subequal in length. Maxilliped inner and outer plates well developed, palp strongly exceeding outer plate, dactyl well developed. Gnathopod 1 coxa tapering, slightly shortened and partly covered by coxa 2, basis broad, without glandular material, carpus longer than propodus, dactyl vestigial, shrouded in setae. Gnathopod 2 coxa tapering, propodus much shorter than carpus, minutely subchelate. Pereopods 3–7 distal articles slender. Uropod 1 peduncle elongate, rami less than 0.6 x peduncle length. Telson elongate, apices not incised.

Etymology. From the Greek, pseudos —lie, added to the common stem of the subfamily ‘- callisoma ’, in reference to historic problems in differentiating the type species of the genus Paracallisoma and the new genus Pseudocallisoma .

Remarks. This new genus is characterised by tapered coxae 1 and 2, slender pereopods 5 to 7 and the elongate peduncle of uropod 1, with the rami less than 0.6 times its length. Austrocallisoma ( Kilgallen & Lowry, 2015) is very similar to Pseudocallisoma in possessing tapered coxae 1 and 2 and slender pereopods 3–7 but can be distinguished by the 1-articulate maxilla 1 palp and absence of maxilliped palp article 4.

Included species. Pseudocallisoma coecum ( Holmes, 1908) comb. nov.; P. platepistomum (Andres, 1977) comb. nov..