116 



1610 Nitidella incerta 



Galapagos Islands. 



1611 Litorina (Tectarius) atyphus 



Manta, Ecuador. 



1612 Nassa brunnesostoma 



Type locality: — near the mouth of the Colorado river, Gulf of 

 Cal. (Edward Palmer). 



Described by Stearns, Nautilus 7:10. 



1613 Williamson, M. Burton: 



Edible mollusks of southern California. Nautilus 7:27. 



1614 Yoldia Monterey ensis 



"Shell large, stout, inflated, with a polished, dark greenish 

 olive epidermis; beaks eroded in all the specimens, situated in 

 the anterior part of the middle third of the shell, not prominent; 

 valves full and rounded, anterior end evenly rounded into 

 the upper and basal margins; posterior end narrower, round- 

 ed, the extreme end nearer the cardinal margin with which it 

 almost forms an angle, below sloping obliquely toward the basal 

 margin, with a very obscure broad ray impressed in a radiating 

 manner from the beaks toward the oblique slope, the profile of 

 which it does not perceptibly indent; surface sculptured only by 

 feeble incremental lines; epidermis polished with 1 or 2 darker 

 concentric color zones and a microscopic, irregular, radially dis- 

 posed wrinkling, most conspicuous at the margins of the im- 

 pressed ray; posterior cardinal margin nearly straight, anterior 

 ditto evenly rounded; interior porcellanous white, the pallial 

 sinus not reaching the middle vertical line of the shell, broad and 

 rather rounded; ligamental fosset large, cup-like; anterior teeth 

 V-shaped, about 22 in number, strong and prominent; posterior 

 teeth similar, and forming an equally long line but only 18 in 

 number, the posterior cardinal margin showing a long narrow 

 impressed area very feebly marked; length of shell 32; beak 

 from anterior end 12; vertical from beak to base 17; max. diam. 

 13 mm." — Dall, Nautilus 7:29. 



Type locality: — Monterey bay, Cal., in 382 fms. 



1615 Acanthochites exquisitus 



Type locality: Los Animas bay, Gulf of Cal. (see Nautilus 

 7:95). 



"Visible portions of the valves extremely narrow, generally 

 less than *4 the entire width of the dried animal. Valves dark 

 olive, interior blue; the girdle light green, tufts very large, either 

 green, pink or bronze; fleshy covered with a green pubescence. 

 Length 30, breadth 18 mm. The valves are more covered than 

 in any other form, the tegmentum being far less in area than one 

 of the sutural laminae." — Pilsbry, Nautilus 7:32. 



1616 Genus Anadenus 



"Animal limaciform, subcylindrical, tapering behind; tenta- 

 cles simple; mantle anterior, concealing an internal shell-plate; 

 no longitudinal furrows above the margin of the foot, and no 

 caudal mucus pore; a distinct locomotive disk; external respir- 

 atory and anal orifices on the right posterior margin of the man- 

 tle; orifice of combined genital system behind and below the 

 right eye peduncle. Internal shell-plate small, oval, flat, with 

 posterior nucleus and concentric striae. Jaw with numerous ribs. 

 Lingual membrane with tricuspid centrals, bicuspid laterals and 

 quadrate marginals." — Binney. 



