Body and head compressed; body short and stubby; scattered papillae on head; eye small; mouth opens at front, oblique; rear of top jawbone vertically expanded, usually with a pointed projection below; jaws with bands of simple teeth; roof of mouth with V shaped band of teeth at front, no teeth at sides of roof of mouth; operculum with a short rear spine, preoperculum with two short teeth at angle; each pelvic reduced to one fine filament inserted under rear part of operculum; dorsal and anal fins joined to tail fin; dorsal rays 95-115; anal rays 76-91; pectoral rays 24-29; lateral line in two or more series of papillae, upper along upper front ¾ of body, lower along midbody from anal fin origin to tail; head and body covered with regularly overlapping scales except top of head and snout, about 100-115 in midlateral series; male penisbony accessory organs.
Dark purplish to nearly black, including fins.
Size: grows to about 20 cm.
Inhabits rocky crevices.
Depth: 5-20 m.
Southern California to the central Gulf of California to Ecuador, the Revillagigedos and Galapagos.