The Pachynidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea) 3246 Author Lowry, J. K. Author Stoddart, H. E. text Zootaxa 2012 2012-03-23 3246 1 1 69 https://biotaxa.org/Zootaxa/article/view/zootaxa.3246.1.1 journal article 10.11646/zootaxa.3246.1.1 1175­5334 5249007 Drummondia tridentata sp. nov. ( Figs 9 , 10 ) Type material. HOLOTYPE , male, 3.8 mm , MV J14616 , south of Point Hicks , Victoria , Australia , 38°17.70'S 149°11.30'E , 400 m , coarse sand, gravel and mud, epibenthic sled, 24 July 1986 , M.F. Gomon et al. , RV Franklin , stn SLOPE 40 . PARATYPE , male, 3.4 mm , MV J14769 , east of Eden , New South Wales , Australia , 37°7.30'S 150°20.20'E to 37°5.30'S 150°21.80'E , 520 m , grey coarse shell, epibenthic sled, 20 July 1986 , G.C.B. Poore et al. , RV Franklin , stn SLOPE 19 . Etymology. The specific name refers to the three dorsal spines on pereonite 5. Diagnostic description. Head lateral cephalic lobe large, broadly rounded; ventral margin subsigmoidal . Antenna 1 peduncular article 1 with posterodistal spine; accessory flagellum 2-articulate, article 1 short; flagellum with strong 1-field callynophore in male, [female not known]. Mandible lacinia mobilis a simple robust seta ; left accessory setal row modified into lamina dentata, right accessory setal row present, not on raised setose ridge; molar absent ; palp attached midway; palp article 2 broad, longer than article 3; article 3 with subparallel margins. Maxilla 1 outer plate with 10 setal-teeth in 7/3 arrangement, outer row setal-teeth with lateral and medial cusps; palp absent. Maxilliped inner plate small; outer plate large; palp 4-articulate, article 4 large. Gnathopod 1 chelate; ischium smaller than propodus, not swollen posteroproximally; carpus extremely compressed; propodus length about 2 × breadth , posterior margin well developed, palm with produced corner, corner of palm with complex robust seta; dactylus reaching to corner of palm . Gnathopod 2 palm minute, obtuse. Pereonite 4 without dorsal spines. Pereonite 5 with 3 acute dorsal spines . Pereopod 5 merus with weak posteroproximal shoulder. Pereopod 6 basis with posteroventral lobe weakly produced; merus as broad as long, with posteroproximal shoulder. Pereopod 7 basis subovate with posterior margin weakly dentate. Epimeron 3 posterior margin without projections, posteroventral corner broadly rounded. Uropod 3 biramous, inner ramus extending less than halfway along outer ramus. Telson shorter than broad, entire. Remarks. Drummondia tridentata is the only species in the genus with a reduced number of setal-teeth on the outer plate of maxilla 1. Distribution. Bass Strait, Australia ; 400–520 m depth.