The state of the apertural
sculpture was scored in two stages.
lip expanded and flaring, slightly reflected and not strongly incrassate.
Colpos con membrana apertural
granular con granulos de [+ or -] 0,2 [micro]m de alto, el tectum escasamente perforado con perforaciones de [+ or -] 0,1 [micro]m, los muros del reticulo de 0,3 a 0,4 [micro]m de ancho y los lumenes varian entre 0,4 - 1,2 [micro]m de diametro.
Margo formando pliegue apertural
de aproximadamente 1 [micron]m, psilado, saliente, y recto a ligeramente ondulado.
Various bulla and unusual apertural
coverings are present in many taxa severely complicating identification.
lip expanded and flaring, reflected and incrassate in holotype.
hunteria wedges its apertural
lip between the gaping valves, propping the bivalve open so that it can be eaten (Wells 1958, Dietl et al.
Although males of most thoracican species show little growth, apertural
males in C.
Colpos de bordes bien delimitados, con membrana apertural
SEM: tectum very perforate, apertural
membrane scabrate (116 of Figs.
Measures included maximum length, maximum width, length of final whorl, length of the spire, apertural
length and width, sutural angle, and number of whorls.
Indice de area apertural
(modificacion del indice de lado apocolpio o I.
Most species of Nucella are well defined, and can be recognized based on apertural
shape and the number and pattern of spiral cords on the penultimate and body whorls.
Kemp and Berthess (1984) found that differences in growth rate induced shell shape variation in Littorina littorea; Appleton and Palmer (1988) showed that Thais lamellosa developed differential aperture characteristics when exposed to waterborne stimuli released by predatory crabs and damaged conspecifics; Lindberg and Pearse (1990) demonstrated that the color and apertural
morphology of the limpet Lottia asmi changed with different substrates and diets.
62), often with only embryonic whorls projecting in apertural
view; final part of last adult whorl descending prior to aperture, but not steeply so; whorls more or less evenly rounded, suture indented; umbilicus very wide, its margin evenly rounded, underside of embryonic whorls clearly visible.