(®gure 9A±H)
Material examined. Holotype female, length 5.8 mm, width 1.5 mm. USNM Cat.
No. 138733.
Type locality. Hatteras abyssal plain, Northwestern Atlantic Ocean, 5325 m Eastward Sta. G-21 (7807).
Etymology. This new species is named in memory of my mother Mrs Jebamoni Roberts. In the Sanskrit language Jeba means prayer and in the Tamil language moni means pearl.
Diagnosis of female. Leutziniscus with female pleon having sharp posterolateral spines. Cephalon almost as long as ®rst and second pereonites combined. Pereonite one signi®cantly longer and larger than second pereonite, more than twice in length. First pereopod robust, not like the slender second pereopod. Coxae of the ®rst pereopod not produced, lacking any setae. Uropod biramous, exopod more than half the length of the endopod, protopod broad.
Description of female. Body unusually large (5.6 mm long) for nannoniscid species in general, nearly twice as long as the average length of 2.8 mm. Body 3.9 times longer than the tergal width of the second pereonite. Fourth pereonite rectangular in shape and the ®fth pereonite squarish, anterolateral angles rounded. Sixth pereonite longer than the seventh pereonite. Pleon with distinct posterolateral spines and posterior margin broadly rounded.
Antennula composed of 11 articles, ®rst article broad and elliptical in shape, second article elongated and longest of all antennular articles, third article almost two-thirds the length of the second article. Flagellum with narrow articles, terminal article not bulbous.
First pereopod robust, basis broad with minute setae on both inner and outer margin; ischium with outer distal margin slightly produced, bearing distal setae; merus with distal outer margin produced, with a long distal seta, dorsal surface with a comb of small setae, distal corner with marginal setae and inner margin with a row of eight seta-tipped spines that decrease in length from proximal to distal. Propodus as long as carpus, with marginal setae on the outer margin and three short seta-tipped spines on the inner margin.
Second pereopod slender, basis narrow and long, lacking any setae; ischium with distal spines; merus short, with setae on inner margin and a spine on outer distal corner. Carpus more than twice as long as merus with a row of seta-tipped spines on the inner margin and a comb of setae on the dorsal surface. Propodus shorter than carpus, with four seta-tipped spines on the inner margin and a row of marginal setae on the outer margin.
Female operculum broad, lacking any ventral hook or spine and the broadly rounded posterior margin with dense small setae. Uropod with broad protopod, exopod well developed, almost two-thirds length of endopod; exopod and endopod well separated from each other at the junction with protopod.
Remarks. Being a monotypic genus, it is not possible to compare this new species with any congeneric species. Nevertheless, there are apparent morphological similarities between this new species and Thaumastosoma platycarpus Hessler, 1970 from the northern North Atlantic ocean at 2886 m. Female of both species have rectangular fourth pereonite and squarish ®fth pereonite. Posterolateral spines are present on the pleon in the male in T. platycarpus but in the female of L. jebamoni. Female operculum has a ventral hook in T. platycarpus but it is absent in L. jebamoni.