“Birubius maldus, new species
Description of female—Head about 20 percent of total body length, greatest width about 55-60 percent of length; rostrum constricted, narrow, elongate, exceeding middle of article 2 on antenna 1. Eyes medium to large, clear of pigment, ommatidia especially large. Article 1 on peduncle of antenna 1 about 1.3 times as long as wide, about twice as wide as article 2, ventral margin with about 9 setules, weakly produced dorsal apex with one setule; article 2 about 0.7 times as long as article 1, with ventral cycle of 4 setae; primary flagellum with 10 articles, about 0.9 times as long as peduncle, aesthetascs weakly developed; accessory flagellum with 8-9 articles. Spine formula on article 4 of antenna 2 = 1-3-4-3 (one hidden in illustration), dorsal margin with notch bearing one seta and one spine, ventral margin with 2 groups of 2-3 long to medium setae, one ventrodistal long spine; article 5 about 0.7 times as long as article 4, facial spine formula = 1-2, dorsal margin naked, ventral margin with 2 sets of 2-3 long to short setae, 2 ventrodistal long to medium spines; flagellum about 1.35 times as long as articles 4—5 of peduncle combined, with 10 articles. Mandibles with strong pal par hump; right incisor with 3 teeth; left incisor with 3 humps in 2 branches; right lacinia mobilis simple, denticulate; left lacinia mobilis with 4 teeth; right rakers 7 plus one rudimentary; left rakers 7-8; molar in form of short protrusion or bulbous hump demarcated mainly by spines, right molar with 4-5 primarily long spines plus one short spine not disjunct, left molar with 4 long spines, each molar with plume; palp article 1 short, article 2 with one medium inner apical seta and one other shorter inner seta, article 3 about 0.9 times as long as article 2, oblique apex with 6 spine-setae, basofacial formula = 0. Inner plate of maxilla 1 thin, bearing one long apical pluseta, one shorter apicomedial seta, 2 apicolateral scarcely shorter setae; palp article 2 with 2 apicalmedial marginal spines and 4 submarginal setae. Plates of maxilla 2 extending equally, of equal width, outer with 2 apicolateral setae, inner with one medial seta. Inner plate of maxilliped with one large, thick, apical spine, 2 apicofacial setae, 3 medial setae, outer plate with 4 medial and apical spines, no apicolateral setae; palp article 1 lacking apicolateral seta, article 2 with one apicolateral seta, medial margin of article 2 moderately to weakly setose, article 3 weakly protuberant, with 2 facial setae, no lateral setae, nail of article 4 long, with 2 accessory setules. Coxa 1 expanded distally, anterior margin straight; main ventral setae of coxae 1-4 = 2-2-2-0, posteriormost seta of coxae 1-3 slightly shortened; anterior and posterior margins of coxa 4 almost parallel, posterior margin very convex, posterodorsal corner rounded, posterodorsal margin short, concave, width-length ratio of coxa 4 = 1:1; long posterior setae on article 2 of gnathopods 1-2 and pereopods 1-2 = 2-3-3-3, long anteriors = 2-3-0-0, short anteriors = 1-1-3-1, no others. Gnathopods ordinary; with ratios of articles 5-6 on gnathopods 1-2 = 22:36 and 25:36, length ratios = 65:60 and 60:61; palmar humps large, palms oblique; article 5 of gnathopod 1 elongate, ovate, posterior margin rounded-flat, article 5 of gnathopod 2 ovate, posterior margin rounded. Pereopods 1-2 similar; facial setae formula on article 4 = 2 and 2, on article 5 = 2 and 2, or 3 and 3; main spine of article 5 extending to M. 80 on article 6, article 5 with one proximoposterior spine; spine formula of article 6 = 3 + 4 and 4 + 4 plus middistal seta, one spine especially long; acclivity on inner margin of dactyls of pereopods 1-2 sharp, produced as tooth, emergent setule long, midfacial pluseta short. Coxae 5-7 posteroventral setule formula = 1—1-1. Articles 4-5 of pereopods $-4 of ordinary width to broad, facial spine rows moderately developed, facial ridge formula on article 2 of pereopods 3-5 = 0-2-2 (anterior short on pereopod 5); width ratios of articles 2, 4, 5, 6 of pereopod 3 = 45:46:39:15, of pereopod 4 = 60:47:28:11, of pereopod 5 = 80:19:15:7, length ratios of pereopod 3 = 75: 31:37:41, of pereopod 4 = 84:47:32:45, of pereopod 5 = 115:25:21:28; article 2 of pereopod 5 reaching middle of article 5; medial apex of article 6 finely combed and bearing 2 obsolescent digital processes. Posteroventral corner of epimeron 1 rounded-quadrate, posterior margin straight, anteroventral margin with one medium seta, posteroventral face with 2 long setae set vertically; posteroventral corner of epimeron 2 rounded-quadrate, posterior margin straight, facial setae = 4-5, posteriormost pair set vertically; posteroventral corner of epimeron 3 rounded, undulant, weakly protuberant, with setule sinus, posterior margin almost straight, ventral margin naked; epimera 1-3 with setule on posterodorsal margin. Urosomite 1 produced ventrally at base of uropod 1, articulation line short; urosomite 3 unprotuberant dorsally. Rami of uropods 1-2 widi articulate enlarged apical nails, outer rami of uropods 1-2 with one accessory setule, outer ramus of uropod 1 with 3 dorsal spines, inner with 2, outer ramus of uropods 2 with 3 dorsal spines, inner with 2 dorsomedial spines; peduncle of uropod 1 with one apicolateral spine and one basofacial seta, medially with one marginal seta and apical enlarged spine; peduncle of uropod 2 with 4 dorsal spines, medially with one small apical spine. Peduncle of uropod 3 with 3 ventral spines, dorsally with one lateral spine, one medial setule; rami feminine to submasculine, inner extending to M. 75 on article 1 of outer ramus, apex with 1-2 setae, medial and lateral margins naked, article 2 of outer ramus ordinary, 0.22, bearing 2 medium to long setae, apicomedial margin of article 1 naked, lateral margin with 3 acclivities, spine formula = 1-2-2-2, setal formula = 0. Telson ordinary, length-width ratio = 12:11, not fully cleft, each apex of medium width, rounded, lateral acclivity narrow, weak, bearing long lateral setule, spine next medial of length equal to setule, midlateral setules diverse. Cuticle with ordinary bulbar setules, setules especially short.
Description of male—Article 2 of antenna 1 with 4—6 ventral setae; primary flagellum with 11 articles, one calceolus each on articles 1-5 or 1-6, aesthetascs very poorly developed; accessory flagellum with 9 articles. Facial formula on article 4 of antenna 2 = 3-4-3, on article 5 = 2, article 5 with 3 dorsal sets of male setae and 0-1 calceolus, distoventral corner with 1-2 thin spines and 0-1 setule; flagellar formula, (25-26), 1, 2, 4, 6 . . . (25 or 26), or 2, 4, 6 . . . . or 2, 3, 5, 7 . . . . Apical seta on article 2 of mandibular palp more elongate than in female, basofacial setal formula on article 3 = 1-1; right rakers = 8 plus one rudimentary; left rakers = 9; each molar with 5 spines and plume. Inner plate of maxilla 1 with only one apicolateral seta instead of 2 as in female; palp with only 5 spines and setae. Outer plate of maxilliped with 6 spines (2 forming pair). Coxa 4 relatively broader than in female, coxa 1 larger in relation to coxa 4
than in female. Long posterior setae on article 2 of gnathopods 1-2 and pereopods 1-2 = 1-1-2-3, long anteriors = 1-2-0-0, short anteriors = 2-2-2-2, no others. Facial setae on article 4 of pereopods 1-2 = 1 and 1-2, on article 5 = 2 and 2, spines on article 6 = 3 + 4 and 4 + 4 plus middistal seta, article 5 with one posterior spine on both pairs. Article 2 of pereopods 3-5 narrower than in female, articles 4—5 of pereopod 4 more elongate, width ratios of articles 5-6 = 26:11, length ratios = 40:54 (in same enlargement as female). Epimera 1-3 broadened, posterior margin of epimera 1-2 strongly protuberant, posterior margin of epimeron 3 shortened; setal formulas, epimeron 1 anteroventral = 1-2, posteroventral = 2 horizontal or vertical, epimeron 2 facial = 3-5, epimeron 3 posterior = 2. Urosome smaller than in female, articulation line of urosomite 1 almost complete. Spine formulas of uropods, uropod 1 peduncle apicolateral = 1-2, basofacial = 1, uropod 2 peduncle dorsal = 8 (12 in supermale), dorsal spines on outer ramus of uropod 1 = 4, of uropod 2 = 3-4, inner ramus of uropod 1 = 2, of uropod 2 = 1 . Ventral spines on peduncle of uropod 3 = 4 (7 in supermale), spine formula on article 1 of outer ramus = 1-1-2-2-2, or 1-2-2-2-2, setal formula = 1-1-1- 1-1. Telson elongate, distal spines shortened. Bulbar setules on cuticle much sparser than in female but cuticle becoming covered with fingerprint striations, grosser in terminal males.
Observations—Larger or older males and females with apices on outer rami of uropods 1-2 becoming attenuate, distance between apex and first distal spine becoming greater and greater; females "a" and "b" each with one egg in brood pouch, female "a" with additional object, perhaps rotted egg.
Illustrations—Female upper lip shown without epistomal part; male upper lip drawn with epistomal part, entire figure drawn from slightly oblique dorsal view, but male without ventral hump; illustration of right (to viewer) side of lower lip with outer margin folded.
Holotype—NMV, female "a," 3.20 mm.
Type-locality—CPBS 12S/3, 18 Mar 1965, Western Port, Victoria, Australia, 2 m, muddy sand.
Voucher material (all illustrated)—Type-locality, female "b," 3.21 mm (with much enlarged eyes); CPBS 51N/1171, male "c," 3.10 mm; PPBES 974/1, supermale "v," 3.27 mm.
Relationship—This species differs from B. taldeus (34) and B. yandus (35) in the nonvillose cuticle and the poor ventral setation on article 2 of pereopod 5. From B. yandus, in addition, it differs in the wide gap between the apex and first distal spine on the outer rami of uropods 1-2. From B.taldeus, in addition, it differs in the parallel anterior and posterior margins of coxa 4 in the female, the presence of only one apicolateral spine on the peduncle of uropod 1 (but supermale B. maldus bears 2 spines and females of B. taldeus often have only 1 spine), the longer spines on the telson,
presence of 2 elements in dorsal notch on article 4 of female antenna 2, elongate apical setae on the inner ramus of uropod 3 of the female, narrower coxae 1-2, longer spines on the peduncle of uropods 2 and the longer rostra and larger eyes in both sexes.
Material—CPBS, 13 samples from 7 stations (22); WPBES. 2 samples from 2 stations (2); PPBES, 19 samples from 10 stations (30).
Distribution—Victoria: Western Port and Port Phillip Bay, 2-25 in, sand, muddy sand, clayey silt, clay.”
(Barnard & Drummond, 1978: 375-380)
