232 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Atlanta guadichaudii Gray, 1850 
Figures of Molluscous Animals, 4:101; PL 241, fig. 4. 
Atlanta, testa vitrea, ovato-discoidea, carinata, tenuissima, pellucida; 
spira minima, planulata; anfractibus quinis, convexo-depressis, ultimo 
carinato; carina basi roseo marginata; apertura ovato-subacuta, antice 
emarginata; peristomate tenui, acuto. (Gray.) 
Atlanta with vitreous shell, ovate-discoidal, carinate, very thin, pellu¬ 
cid; spire small, conical, slightly projecting; five whorls, somewhat de¬ 
pressed; the last whorl provided with a carina; aperture ovate-acute, 
emarginate in front; with acute peristome, slightly reflexed, laterally 
roundly projecting. (Translation.) 
Range. Pacific Ocean. Pelagic. 
Atlanta cunicula Gould, 1852 
Mollusca and Shells of the United States Exploring Expedition, 492; PL 51, fig. 598. 
T. fragilissima pellucida, nautiloidea, sub-circularis, compressa, carina 
latissima cincta; apertura elliptica, acutangularis. (Gould.) 
Shell very delicate, with a keel nearly as broad as the shell itself, nearly 
circular, compressed, quite simple, merely exhibiting very faint lines of 
growth. (Gould.) 
Type in United States National Museum. Type locality, latitude 
28° N., longitude 178° E., to the westward of the Sandwich Islands. 
Range. North Pacific. Pelagic. 
Atlanta helicinoidea Gray, 1850 
Figures of Molluscous Anitnals, 4:101. Voyage ... la Bonite, Atlas, PI. 120, figs. 
23-30. 
Atlanta, testa vitrea, discoida, late carinata, pellucida, tenuissima; spira 
minima, exserta, conica; anfractibus septenis, convexo-depressis; ultimo 
carinato; carina basi ferrugineo marginata; apertura ovato-acuta, antice 
emarginata; peristomate tenui, acuto. (Gray.) 
Atlanta with vitreous shell, discoidal, broadly carinate, pellucid, very 
thin; with very small spire, projecting, conical; with seven convex-de¬ 
pressed whorls; the last one carinate, the carina bordered with a rusty- 
brown base; aperture ovate-acute, emarginate in front; peristome thin, 
acute. (Translation.) 
Type locality, Pacific Ocean. 
Range. Pacific Ocean. Pelagic. 
[ 530 ] 
