Iiella

Fukuoka, Kouki, 2011, A new species of the genus Iiella Băcescu, 1968 (Crustacea: Mysida: Mysidae) from Malaysia, with notes on I. elegans (Tattersall, 1960), Zootaxa 3091, pp. 60-68 : 67-68

Key to the species of Iiella

1. Apical cleft of telson with anterior end extending to ultimate lateral spiniform seta, and forming rounded space in anterior part.................................................................................................... 2

- Apical cleft of telson with anterior end extending beyond ultimate lateral spiniform seta, and not forming rounded space.... 3

2. Rostral plate rather narrow with deeply concave lateral margins; labrum armed with 3 or 4 spines on each side of median long spine; uropodal endopod armed with 12 or 13 spinifrom setae on mesial margin....................... I. hibii ( Ii, 1964)

- Rostral plate broad; labrum armed with 1 or 2 spines on each side of median long spine; uropodal endopod armed with 6 or 7 spiniform setae on mesial margin......................................... I. iriomotensis Fukuoka & Murano, 1997

3. Anterior end of apical cleft of telson extending to or beyond antepenultimate lateral spiniform seta..................... 4

- Anterior end of apical cleft of telson not extending to antepenultimate lateral spiniform seta.......................... 5

4. Labrum armed with 2 or 3 spines on each side of median long spine; setae on middle part of lateral spiniform seta of telson arranged in groups with short and long setae...................................................... I. malayensis

- Labrum armed with 4–6 spines on each side of median long spine; lateral spiniform setae of telson subequal in length.......................................................................................... I. ohshimai ( Ii, 1964)

5. Telson 3.2–3.4 times as long as broadest part................................................ I. pelagica ( Ii, 1964)

- Telson 2.4–3 times as long as broadest part.................................................................. 6

6. Telson armed with 8–11 spiniform setae on lateral margin.................................... I. formosensis ( Ii, 1964)

- Telson armed with more than 13 spiniform setae on lateral margin............................................... 7

7. Rostral plate rather broad; uropodal endopod armed with 17 short spiniform setae on mesial margin.... I. elegans ( Tattersall, 1960)

- Rostral plate narrow with deeply concave lateral margins; uropodal endopod armed with 7–12 slender spiniform setae on mesial margin............................................................................................................................................................................................. 8

8. Carpopropodus of endopod of third to eighth thoracopods divided into 5–7 subsegments; apical cleft of telson 0.14–0.17 of telson length.................................................................... I. hispida Jo & Murano, 1992

- Carpopropodus of endopod of third to eighth thoracopods divided into 8–15 subsegments; apical cleft of telson 0.13 of telson length..................................................................... I. kojimaensis ( Nakazawa, 1910)