"CERION AGUAYOI, sp. nov. Plate 6, figs. 6, 7. Shell solid, rimately umbilicate, cylindrical to subcylindrical. Most specimens slightly wider above the middle. Color white to greyish white. Interior of aperture occasionally slightly pink-yellow. Whorls flat, 9 ½ to 10 ½. First two nuclear whorls glassy, striate axially with fine hair like ridges. remaining whorls opaque. The axial striation is generally lost beyond the fifth whorl though some specimens retain the striation throughout. Spire forming usually an angle of about 90°. The angular portion is composed of six to seven whorls, the remainder are more of less flat sided. Aperture rounded to rounded-ovate; fully adult specimens are somewhat holostomous, in others the parietal wall is lightly calloused. Peristome white, reflected. Columella straight. Parietal tooth well centered, but not sharply developed. Columellar tooth usually present but slightly developed, occasionally obsolete or reduced to a slight thickness on the columella. Sutures very slightly indentated. Sculpture composed of axial growth lines irregularly spaced on the majority of specimens examined. Certain specimens, however, exhibit a strong tendency to develop axial ribs which are an apparent outgrowth of the sculpture exhibited on the early whorls of all specimens. On the basal area of the body whorl the riblets become fine and more numerous.
Length Width Ap.length Ap. width
26 mm 14.5 mm 8 mm 7.5 mm Holotype
23 " 13.5 " 7 " 6 " Paratype
23.5 " 13 " 6.5 " 5.5 " Paratype
23.5 " 13 " 7 " 6 " Paratype
24.5 " 13 " 7 " 5.5 " Paratype
25.5 " 15 " 8 " 6 " Paratype
26 " 13.5 " 7 " 5.5 " Paratype
26.5 " 14.5 " 8 " 6 " Paratype
26.5 " 15 " 8 " 7 " Paratype
29 " 14 " 8.5 " 7 " Paratype
Holotype: M. C. Z. No. 47902, Road to Caltones, about 6 Km. W. of Gibara, Oriente, Cuba. C. G. Aguayo, collector, August, 1927. Paratypes: M. C. Z. No. 47903 and 52783, and in collections of C. de la Torre and C. G. Aguayo.
This species belong to the group of C. proteus Gundlach, and like it is found in Gibara, Cuba. C. aguayoi is restricted to a very small area about 4 miles from C. proteus. It differs from C. proteus by its smaller size and by the shape of the shell, the apex being rounded, less obtuse. In C. proteus the whorls are very flat and irregularly at the sutures, often protruding slightly beyond the next whorl. An occasional specimen of C. aguayoi shows a trace of the peculiar condition." (de la Torre & Clench, 1932: 89)
