Dendrochiton lirulatus (Berry, 1963)

(Figures 3A, 8A–H)

Dendrochiton lirulatus Berry, 1963: 135–138 . Chresonymy and synonymy in Kaas & Van Belle (1985b) and Ferreira (1982).

Type material. Holotype, SBMNH 34440 from the “Berry collection 29879”.

Type locality. North shore of Bahía San Felipe, Baja California.

Material examined. Three specimens, BL 8.5–17.1 mm.

Habitat. On large rocks with brown and red crusty algae. The rocks were found in an exposed area, dry during the low tide. The chitons were collected on rocks, buried in sand, in a moist environment.

Remarks. The sculpture of Dendrochiton lirulatus has irregular pits arranged in quincunx (Figs. 8A, C); lateral areas with eroded sculpture and remains of smaller pits near the apex area (Fig. 8B); intermediate areas with 12–15 longitudinal coarse ribs (Figs. 8B, C). Tiny elongated dorsal girdle spicules with an apical nipple–like top (Fig. 8G); long, branched bristles (Figs. 8E–F). Major lateral radular tooth tricuspid, minor lateral tooth smaller and shorter than the central tooth, which appears as a sub–rectangular plate (Fig. 8H).

Dendrochiton lirulatus is the only species of this genus in the Gulf of California. It is characterized by longitudinal ribs on the central areas of the intermediate valves, a girdle with tiny spicules, and tufts of ramified corneous hairs. According to Kaas & Van Belle (1985), the distribution of this species is confined to the north of the Gulf of California, from Bahía San Felipe, BC and Bahía la Choya, Puerto Peñasco down to Guaymas, Sonora. The specimens studied herein come from the known distribution range.