natural, history

ARIOPHANTIDAEQuiroselJa. new genusShell depressed to globose, imperforate or with an imperfectly closed umbilicus.Sculpture consisting of fine growth lines and exceedingly fine spiral threads; nuclearwhorls entirely smooth.This new genus appears to be close in its relationships to Nesonanina Bgt. of theAdmiralty Islands. It differs in not having the dome shaped spire of Nesonanina andin having rather deeply incised sutures. The general shape of the two are quitedifferent yet difficult to describe. Quirosella appears to be more remotely related toHemiplecta Albers. a genus of wide distribution in the western Pacific islands. Fromthis genus. Quirosella differs in being imperforate or nearly so. in lacking all sculptureother than occasional specimens with very fine spiral threads and in not havingthe peculiar color pattern which occurs in Hemiplecta. In this latter genus bothsculpture and color may differ quite remarkably on the whorls above and below theperiphery.Type species, Quirosella coultasi Clench.Quirosella coultasi, new species(Plate 18. fig. 1-2; text fig. 2. p. 191)Desc r i pt ion. Shell globose. relatively solid. imperforate or with a minute umbilicalopening. Color a uniform dark yellowish brown or with two bands of a much darkerbrown, one above and one below the periphery. Whorls 5 and strongly convex. Asmall rounded lip margins the aperture which is colored a \ery pale pink in freshspecimens. Fully matured specimens have a small tooth-like thickening on ti'.ecolumellar margin of the lip with a second thickening on the basal margin of the lip.Sculpture offine and somewhat irregular growth lines. On a few of the paratypes thereare very faint and very fine hair·like spiral threads. Columella oblique and thickenedbelow with the tooth-like process. Outer lip in profile produced in a narrow sigmoidcurve. Aperture cast at an angle of 40" from the axis (50' from the base line).Height Width Aperture Width13.2 mm 14.4 17 mm 8 mm Holotype13.8 - 15 17.4 - 7.6 - Paratype12 15.3 , 17.5 -- 8.1 -13.5 - 14.5 17 S11.8 _- 14.5 16.5 - 6.5 -Types. Holotype, American Museum of Natural History no. 59011. from RennellIsland, Solomon Islands. W.J. EYERDAM collector. May 25, 1930. Paratypes fromthe same locality in the American Museum Natural History no. 59012. the Museumof Comparative Zoology no. 93017, the Dominion Museum,Wellington, New Zealand,175