Cranocephalus scleroticus (Streets, 1878)
Oxycephalus scleroticus Streets, 1878 (1879): 281‒283, pl. 2, fig. 3a, b, c.
Cranocephalus scleroticus .— Bovallius, 1890: 95‒97, pl. IV, figs. 7‒9; Brusca, 1981: 13 (list), 32 (key), 45, fig. 22b, d, f; Siegel-Causey, 1982: 343‒344; Vinogradov et al., 1996: 532‒534, fig. 230; García Madrigal, 2007: 156 (list); Gasca, 2009: 89 (tab. 1); Lavaniegos & Hereu, 2009: 152 (appendix); Gasca et al., 2012: 126 (tab. 1), 127‒136 (passim); Valencia & Giraldo, 2012: 1493 (tab. 1); Valencia et al., 2013: 52 (tab. 1); Zeidler, 2016: 96‒99 (passim), figs. 47‒48.
Cranocephalus goesi Bovallius, 1890: 21, fig. 5, 32, fig. 53, 38, fig. 72, 95‒97, pl. IV, figs. 7‒9.
Oxycephalus typhoides Claus, 1879: 49 .
Material examined. 2M, 1F in three localities (Fig. 1).
TALUD III. St. 19 (25°12’00”N, 109°07’00”W), August 20, 1991, 1M, I-K, surface to 410 m (TD, 920 m) (ICML-EMU-12944-A); St. 19B (25°18’24”N, 109°18’36”W), August 20, 1991, 1F, I-K from surface to 600 m (TD, 1890 m) (ICML-EMU-12944-B). TALUD VII. St. 36 (25°42’37”N, 110°04’35”W), June 9, 2001, 1M, MN from surface to 1390 m (TD, 2400 m) (ECOSUR-10557) .
Distribution. Circumtropical, from 40°N to 40°S. In the eastern Pacific from Alaska to Colombia (Vinogradov et al. 1996, García Madrigal 2007, Valencia & Giraldo 2012, this study).
Remarks. The only female collected in this study (7 mm length) features the rounded head as illustrated in Shih & Chen (1995).
According to Siegel-Causey (1982), C. scleroticus was very rare in the Gulf of California, where it was found only in the northern Gulf. Records in our study are all from the southern Gulf (Fig. 1). Lavaniegos & Hereu (2009) reported this species from the Mexican portion of the California Current.