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Analogium spec. nov. 2
(fig. 4a-c, pl. 3 fig. 2)
? Gymnodoris sp. Wells & Bryce, 1993: 89, sp. no. 102.
? Gymnodoris sp. 1 Debelius & Kuiter, 2007: 83 (Bali).
Material.— RMNH.MOL.131666, RBE Stn 30, Suli, Ambon, 5-7 m depth, 29.xi.1990, leg. A. Fortuin, “small orange active nudibranch in sand,” 5 × 2 mm pres., photos M. Lavaleye 35-3/4.
Description.— The body was white with large slightly raised yellow-orange pustules and a continuous single row of elongated pustules along the pallial line, head, and top of the tail; an additional row of pustules was present along both sides. Sixteen pustules on the dorsum were loosely arranged in longitudinal series in front of the gills but in no definite pattern beyond the gills (pl. 3 fig. 2). No pustules or colour marked the margins of the foot. The genital aperture was located on the right side close to the rhinophore, approximately one-third of the distance between the rhinophores and the gills. The rhinophores were retracted in the photographs, but appear to have been white without orange tips. Thirteen gills are arranged in a transverse row, touched with yellow-orange on their frontal surfaces.
The preserved specimen is minute and appears to have partially dried out at some point. The buccal bulb projects out of the mouth (also visible in pl. 3 fig. 2), and the conical genital papilla is located below and behind the right rhinophore. The elongated rhinophores have six overlapping diagonal lamellae and a round terminal knob (fig. 4a). The gills are all united basally and each branch is simply pinnate (fig. 4b). The radula is missing but some pieces and a few teeth were obtained from the storage vial, appearing form a complete half row of 8-9 teeth (fig. 4c). The first lateral differs from the remainder, small with three spikes on the end; the larger second tooth is bent in the middle, nearly 90o; the remaining teeth straighten along the row and have a small square base with a long cusp. The second and remaining laterals have a small peg at the base where the cusp meets the base; this becomes smaller near the end of the row.
Remarks.— Despite the lack of recent literature on the genera Gymnodoris and Analogium and the very small size of this specimen, this species is distinct from the named species of Analogium as well as from the new species described above. The genus was first introduced by Risbec (1928) and resurrected by Hamatani (1995) to distinguish those gymnodorids with a transverse band of plate-like gills, but this is not accepted by some authors (Rudman & Darvell, 1990; Gosliner et al., 2008). There are several illustrations of spotted species of Analogium from the western Pacific (e.g. Wells & Bryce, 1993; Gosliner et al., 2008; all as Gymnodoris) so it is more prudent to await more material. Externally, Analogium spec. nov. 2 differs from known species in having raised pustules instead of ridges although consideration must be given to its small size: the 22— 24 mm specimens of A. striatum illustrated by Hamatani (1995) show the dorsal ridges broken up into pustules, although the pallial margin is a continuous ridge. The radulae of all four species are extremely similar, as illustrated by Vayssière (1912), Baba (1937, 1996), Hamatani (1995), and in this work. It is probable that the rows available for this specimen are complete half rows; in comparison, there were 6-18 teeth in the rows of the radula of a 25 mm specimen of A. striatum (Hamatani, 1995).