CLASS GASTROPODA 
233 
Atlanta quoyii Gray, 1850 
Figures of Molluscous Animals, 4:101. Voyage ... la Bonite, Atlas, PI. 20, figs. 16-22. 
Atlanta testa vitrea, ovato-discoidea, carinata, tenuissima, pellucida; 
spira minima, conica, exsertiuscula; anfractibus quinis, depressiusculis; 
ultimo carina instructo; apertura ovato-acuta, antice emarginata; peristo- 
mate acuto, reflexiusculo, lateriter rotoundatim productiusculo. (Gray.) 
Atlanta with a vitreous shell, ovate-discoidal, crenate; very thin pellu¬ 
cid, with very small spire, conical, very slightly projecting; with five whorls 
slightly depressed; the last one provided with a carina; aperture ovate- 
acute, emarginate in front; peristome acute, somewhat reflexed, on the 
sides roundly very slightly produced. (Translation.) 
Range. Pacific Ocean. Pelagic. 
Genus OXYGYRUS Benson, 1835 
Shell milky, narrowly umbilicated on both sides; nucleus not visible; 
back rounded, keeled only near the aperture; body whorl, near the aper¬ 
ture and keel cartilaginous; no apertural slit; operculum trigonal, lamellar. 
Type. Oxygyrus keraudrenii Rang. 
Distribution. Atlantic, Pacific, and Mediterranean. 
Oxygyrus rangi Loven, 1847 
Ofversigt af Kotigl. Vetcnskaps-A kadetniens For handling ar, 491; PI. 44. V oyage . . . 
la Bonite, Atlas; PI. 18, figs. 18-20. 
Atlanta, testa vitreo-membranacea, sub-orbiculari, symmetrica, involuta, 
utrinque umbilicata, late carinata, tenuissima, translucida; anfractibus 
ternis, convexis, levigatis, in utroque umbilico perspicuis, tenuissime 
striatis; ultimo supra carina lata instructo, subtus non carinato; apertura 
magna, cordiformi, antice canaliculata; peristome sinuoso et acuto, postice 
interrupto. Operculum vitreum, subtriangulate, tenue, pellucidum, stri¬ 
atum. (Gray.) 
Described as Atlanta. 
Atlanta with vitreous-membranous shell, suborbicular, symmetric, in¬ 
volute, umbilicate on both sides, broadly carinate, very thin, translucent; 
with three convex whorls extended, perspicuous in each umbilicus, most 
finely striated; with the last whorl provided with a broad carina above, not 
carinate below. Aperture large, cardiform, canaliculate in front, with 
peristome sinuous and acute, interrupted in the rear. Operculum vitreous, 
subtriangular, thin, pellucid, striate. (Translation.) 
Range. Pacific Ocean, off Monterey, California. Pelagic. 
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