CLASS GASTROPODA 
49 
bilobed, and without a flagellum; front edge of the velum slightly exca¬ 
vated; parapodia wide, the sole slightly longer than the body; shell 
internal, subconical, white, covered with a brownish epidermis; pillar 
strong, reflected with a deep groove outside of it, the basal end projecting 
spur-like; nucleus small, depressed. (Dali.) 
Type in United States National Museum. Type locality, Eagle Harbor, 
Puget Sound, in 20 fathoms. 
Range. Known only from type locality. 
Genus NAVANAX Pilsbry, 1895 
Body elongated, similar in general character to Aglaja, but anterior 
angles of head-shield produced to form short involute rhinophores. Shell 
as in Aglaja . (Pilsbry.) 
Type. Navanax inermis Cooper. 
Distribution. West America. 
Navanax inermis Cooper, 1862 
Proceedings of the California Academy of Sciences, 2:202. Manual of Conchology, 16: 
PI. 15, figs. 89-93. 
Back of the body, foot, and outside of pleuropodia wine-purple, orna¬ 
mented with rounded or oblong spots of yellow; inner sides of pleuropodia 
flesh-colored. Free edges of pleuropodial lobes and inner edges of the 
tail lobes and rhinophores orange-colored with adjacent band and alternat¬ 
ing spots of blue; lower side of tail-lobes purple-blue; eye-patches white 
with black centers. Length, 2 y 2 ; breadth of body proper, % in. (living 
animal). Shell quite thin and completely flexible, brownish-yellow, without 
trace of calcification. (Tryon and Pilsbry, Manual of Conchology.) 
Type in California State Collection. Type locality, San Diego Bay, 
California. 
Range. Catalina Island to San Diego, California. 
Family APLYSIIDAE 
Genus TETHYS Linnaeus, 1758 
Shell very thin, membranous with a thin calcareous inner layer, nearly 
as large as mantle, concave, with pointed, small apex, bearing a recurved 
lamina, and having a concave posterior sinus. (Tryon and Pilsbry, Manual 
of Conchology.) 
Type. Tcthys leporina Linnaeus. 
Distribution. All tropical and warm temperate seas. 
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