Antennuloniscus menziesi George 2004, n. sp.

Antennuloniscus menziesi n. sp.

(figure 15)

Diagnosis. Antennuloniscus with cephalon lacking frontal projection and posterolateral angles projecting well beyond the median margin of the pleotelson. Pereonite 7 fused mid-dorsally with the pleotelson. Antenna 1 with foliaceous basal article. Flagellum of antenna 2 with eight articles.

Material examined. Holotype: male, length 2.5 mm, width 1.0 mm. USNM Cat. No. 138683.

Type locality. R / V Eastward Sta. G-6238, site Beta over the Carolina lower slope.

Etymology. This new species is named in honour and memory of the late Prof. Robert J. Menzies of the Florida State University with whom I had the joy of participating in several oceanographic cruises and describing new genera and many new species of deep-sea isopods. Dr Menzies described 34 deep-sea haploniscid isopod species as author or co-author and is known for the classical work The Isopods of the Abyssal Depths of the Atlantic Ocean (Menzies, 1962).

Description. Body somewhat quadrangular in shape, with anterior margin of cephalon lacking any median convexity or spine. Anterior three pereonites subequal. Pereonite 4 twice as long as the third. Lateral sutures distinct between pereonites 1 and 5, more pronounced between pereonites 4 and 5. Pereonite 7 fused mid-dorsally with the pleotelson. Pleotelson shield-shaped, posterolateral angles acutely produced far beyond the rounded apex.

Antenna 1 with large foliaceous basal article, second peduncle article narrow and elongated, flagellum of five articles, terminal two articles furnished with long aesthetascs. Antenna 2 with peduncle article 3 much longer than the basal two articles combined; the whip-like flagellum composed of seven articles. Male pleopod 1 with distal lobes medially separated and bearing four distal setae. Male pleopod 2 with a strong and stout stylet. Uropod uniramous, tip of ramus not reaching to one-third the length of the posterolateral projection.

Remarks. Antennuloniscus menziesi n. sp. resembles A. dimeroceras (Barnard, 1920) from 1280–5843 m in both north and south Atlantic, and A. armatus Menzies, 1962 from 458–4960 m in the south Atlantic off South Africa, in having the posterolateral angles of the pleotelson projecting beyond the apex. In both these species pereonite 7 is fused with the pleotelson. However, A. menziesi n. sp. differs from A. dimeroceras in lacking the median convexity on the frontal margin of the cephalon. This new species is also clearly distinguished from A. armatus which has a pronounced median spine on the frontal margin of the cephalon, and pereonite 7 is not fused with the pleotelson.