208 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Plicifusus verkruzeni Kobelt, 1876 
Jahrbuch der Malakozoologische Gescllschaft, 1876, 70; PI. 2, fig. 1. 
Testa ovato-turrita, cauda brevissima, solida, fere laevis; anfr. 8+, 
rotundatis, leniter accrescentes, ultimus dimidiam testae non aequans, ad 
suturam parum impressi, oblique striatuli, spiraliter sub lente vix conspicue 
striati, sutura subcanaliculata; apex obtusulus, sumnio minuto, conico; 
apertura ovata in canalem brevem, patulum desinens, labro simplice, faux 
laevi, columella superne parum, inferne fortiter callosa, parum arcuata. 
Sordide albida, epidermide tenuissima, laevi, flavo-viridescente induta, 
apertura roseo-albida. Operculum tenue, corneum, subovatum, nucleo ad 
apicem inferiorem sito, striis conspicuis. Long. spec, majoris, 50; lat. 
max., 22; alt. apert., 20 mm. (Kobelt.) 
Shell ovately turreted, with a very short solid canal, almost smooth; 
with 8 rotund whorls, increasing slowly in size, the last not equaling the 
half of the shell, little impressed at the suture, obliquely striate, spirally 
scarcely conspicuously striate under the lens, suture subcanaliculate; apex 
slightly obtuse, apex minute, conical; aperture ovate, extending into a 
broad canal; with simple lip, mouth or throat smooth, columella above 
little and below strongly callous, little arcuate. Dully whitish, covered 
with a very thin epidermis, smooth, greenish-yellow, aperture roseate- 
white. Operculum thin, corneous, subovate, nucleus situated on the lower 
apex, with conspicuous striae. (Translation.) 
Type in Museum Frankfurt. Type locality, Arctic. 
Range. Arctic Ocean to Bering Strait; circumboreal. 
Subgenus Retifusus Dali, 1916 
Plicifusus incisus Dali, 1919 
Plate 13, fig. 5 
Proceedings of the United States National Museum, 56 :314. 
Shell of moderate size, whitish, with a yellowish-brown periostracum 
and about seven well-rounded rapidly increasing whorls, the nucleus 
eroded; suture distinct, deep; axial sculpture of numerous retractively 
arcuate small plications with subequal interspaces, extending from suture 
to suture, but becoming obsolete on the last part of the last whorl; the 
incremental lines evident but not conspicuous; spiral sculpture of (on the 
penultimate whorl about 8) flattish pairs of spirals divided by a shallow 
groove and the pairs separated by deeper, narrower, somewhat channeled 
grooves; between these and the preceding suture is a narrow band of 
closer threads; the former sculpture extends to the canal with much uni- 
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