. Bulletin - United States National Museum. Science. 206 NATIONAL MUSEUM BULLETIN 25S. Figure 57.—Pleusirus secorrus, new genus, new species, female, mm., Campbell station 5: a, head and epistome-upper lip complex; b, pereopod 5; c, upper lip. Specimen, station 1871: d,e, maxilla 1;/, maxilla 2; g, shape of outer lobe of maxilla 2; h, lower lip. Female, mm., station 43-B-2: i,j, mandibles; k, maxilliped. Pleustes depressa Alderman and Pleustes platypa Barnard and Given Figure 58 Pleustes depressus Alderman, 1936, pp. 56-58, figs. 14-18.—Hewatt, 1946, p. 199 — J. L. Barnard, 1954a,
. Bulletin - United States National Museum. Science. 206 NATIONAL MUSEUM BULLETIN 25S. Figure 57.—Pleusirus secorrus, new genus, new species, female, mm., Campbell station 5: a, head and epistome-upper lip complex; b, pereopod 5; c, upper lip. Specimen, station 1871: d,e, maxilla 1;/, maxilla 2; g, shape of outer lobe of maxilla 2; h, lower lip. Female, mm., station 43-B-2: i,j, mandibles; k, maxilliped. Pleustes depressa Alderman and Pleustes platypa Barnard and Given Figure 58 Pleustes depressus Alderman, 1936, pp. 56-58, figs. 14-18.—Hewatt, 1946, p. 199 — J. L. Barnard, 1954a, p. 9. Pleustes platypa Barnard and Given, 1960, pp. 41-42, fig. 1. Pleustes platypa shows some evidence of gene flow with P. depressa in its variable rostrum, ranging from the very elongated shape shown in the type series to the shorter kind shown in the figures herein; nevertheless, the two species remain distinguished everywhere but at the La Jolla locality by the shape of the dorsal segmental teeth which are rounded in P. depressa and sharp in P. platypa. The dorsal segmental teeth are highly variable in development in P. platypa as shown in the accompanying table (p. 207). To some extent the Pt. Conception zoogeographic boundary holds good for these two species, P. depressa being confined north of the point and P. platypa south of the point, except at La Jolla. Specimens from La Jolla lack dorsal teeth and have rostra similar to P. depressa but all are juveniles to mm. long. A preliminary examination of specimens at hand from Puget Sound, Washington, indicates the extreme plasticity of specific characters and suggests the possibility that the southern species may be linked with those of the Arctic-boreal in a common Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United State
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