natural, history

Chloritis (Sulcobasis) quercina hombroni Pfeiffer, PILSBRY 1894, Man. of Conch.,(2),9: 121; GUDE 1906, Proc. Mala. Soc. London, 7: 114; CLAPP 1923, Bull. Mus.Compo Zoo!., 65: 382.Remarks. Judging from the material obtained by EYERDAM, this form is a littlemore abundant than E. quercina and is associated with it at nearly every locality.As stated by PILSBRY (1890, p. 257), it completely intergrades with the typical form.We have retained the name hombroni as a form only under quercina becauseextreme specimens of both quercina and hombroni are so different as to size and toa less degree in shape.Specimens examined. Bougainville: Kieta. Choiseul: Choiseul Bay;Luti; Bambatana. Florida. Ysabel: Fulakora.Eustomopsis renscbi, new species(Plate 19, fig. 9-10)Descri ption. Shell medium in size, depressed, umbilicated, rather heavy. Color inlive material probably a deep red brown. Whorls 5, bluntly keeled, the keel high oneach whorl producing a shoulder. Spire very depressed and slightly concave. Apertureoblique and somewhat auricular in shape. Lip strong and well reflected with a slightthough very definite indentaion on the outer side. Parietal wall very thinly callouse6.Columella very short and curved outwardly. Sutures fine and indented. Sculpture ofrather short periostracal hairs arranged in oblique rows producing the quincuncialpattern. On shell areas denuded of the periostracum, th~ little knobs are well pronounced.These are the insertion areas for the hairs. The remaining sculpture is offine, somewhat oblique, growth lines. Angle of spire 144 -, aperture cast at an angleof about 18: from the axis.Length16.5 mm20.5 -37.4 mm40.5 -17.5 5.5 mm19 6.5-HolotypeParatypeTypes. Holotype. American Museum of Natural History no. 66463, Tulagi, Floridagroup, Solomon Islands, W.J.EYERDAM collector, April 20, 1930. Paratype, Museumof Comparative Zoology no. 92957. same data as holotype.Remarks. This species is very probably an extreme development of the E. quercinahombroni stock and has evolved its distinctive form through isolation on Florjda.A parallelism of this sort is as well expressed by C. isis which represents the extreme. flattened form of the Sulcohasis series.The open umbilicus of E. rimschi is somewhat funnel shaped and in part coveredby the reflected lip at the columellar area.198