The single immature shell in hand includes the protoconch and the first teleoconch whorl. It is characterized by I) protoconch turbiniform, of 3 convex, smooth whorls, 2) columella weakly pli¬cate, 3) outer lip thin, with 7 elongated teeth on its inner side, 4) siphonal canal short, oblique, 5) sculpture of 2 prominent varices placed in one plane and of collabral ribs and overriding spiral cords forming a lattice pattern with weak, spirally elongated nodes at the intersections; 6 ribs are present between the varices. DISTRIBUTION AND HABITAT. Gyrineum pusillum is widely distributed in the Indo-Pacific, from South Africa to Hawaii and from Australia to Southern Japan. It occurs on rocks, coral rubble, sand and sandy mud intertidally and subtidally down to 100 m depth (HABE, 1968; KAY, 1979; ABBOTT & DANCE, 1982).
FOSSIL RECORDS. Mid-Late Miocene of Indonesia; Late Pliocene of Philippines; Quaternary of In¬donesia and Philippines.

As noted under Gyrineum lacunatum. Broderip's only undoubted syntypes of Ranella pusilla are while shells with a bulbous protoconch of only 0.8 whorls, clearly distinct from the multicoloured species with a turbiniform protoconch of 1.8-2.2 whorls that has usually been known as G. pusillum. The syntypes of G. pusillum are small (13.4 to 16.5 mm high), narrow, evenly and finely nodulose, white shells with very low varices. The type locality is "Lord Hood's Island" (South Marutea Island. Tuamolu Islands: DANCE, 1966: 148; DANCE, 1980). The sole figure of the true G. pusillum in early iconographies is that by G.B. SOWERBY II (1835: pl. 84, fig. I) which appears to have been based on the specimen here designated the lectotype. The identity of the true G. pusillum has, however, been recognised from specimens collected in eastern Polynesia by Jean Trondle, who kindly made them available for examination. These two lots (two specimens from Tubuai in the Austral Islands, and two from Rapa) were identified by Trondle as G. roseum and, indeed, closely resemble western Pacific specimens of G. roseum in shape and sculpture. They differ most obviously from G. roseum in their very elevated and wide, bulbous protoconch initiation, producing a protoconch of only about 0.8-0.9 whorl, in their narrower shape, and in their white to pale pink or pale orange-yellow coloration, rather than the consistent dark pink, with yellow nodules, of G. roseum. It therefore seems likely that the uniform pale pink specimens from Raivavae, in the Austral Islands, illustrated by SALVAT & RIVES (1975: 306, fig. 175) are G. pusillum. All these eastern Polynesian specimens, including Broderip's type material of G. pusillum, have uniform sculpture of even rows of low nodules, without the large, fused nodules seen on many G. roseum. have lower, narrower varices than in G. roseum, and have very clearly and sharply margined spiral cords rather than the indistinctly margined cords, merging smoothly with their background, seen on G. roseum. The overall similar appearance of all these specimens to G. roseum suggests the possibility that there is an east-west cline in protoconch whorl numbers and that G. roseum and G. pusillum might be conspecific, but much more material from eastern and central Polynesia is needed to evaluate this. Apparently restricted to eastern Polynesia.

Gyrineum pusillum (Broderip, 1832). (Synonyms: Triton lacunatum Mighels, 1845; Gyrineum polychlorum Tapparone, Edmondson, 1933.) Length, 12 mm; diameter, 9 mm. Shell: compressed, bordered on each side by a lateral varix; aperture purple. Spire: attenuate, whorls compressed, suture impressed. Sculpture: variable reticulated to nodulous, with fine spiral cords crossed by axial grooves; varices forming two ribs, one on each side. Color: banded with white, blue, and rose; aperture purple, sometimes cream with a rosy aperture. Specimens are not uncommonly collected under rocks in tide pools, and have been recorded to depths of 104 m. This species is widely distributed throughout the Indo-West Pacific from the Seychelles to southern Japan and Okinawa, and Polynesia. The shells are variable in sculpture and color, and some of the forms have been assigned different names such as G. var. rosea (Reeve, 1844) and G. cuspidataeformis (Kira, 1956).