Sinoennea callizonus van Benthem Jutting, 1961
“Sinoennea callizonus has a much narrower umbilicus than either charasensis, hungerfordiana, perakensis or tweedei. S. kanchingensis is a large, spindle-shaped species without palatal teeth. S. malaccana is somewhat compressed dorso-ventrally. The minute S. lembingensis is quite different in size, shape and style of ribbing. S. chintamanensis is a much larger, ventricose shell, with two columellar teeth. Its two palatal teeth are implanted on a common base. S. pagodella is much more slender, with a blunt top. It possesses two columellar teeth, and the peristome is juct free. S. apicata is more pointed at the top, with fewer ribs on the last whorl. In the aperture it has only one palatal, but two columellar teeth. S. crumenilla has a more obese shell, with a distinct swelling at the distal end of the last whorl in the umbilical region behind the peristome. The distance between parieto-angular lamella and the palatal teeth is very narrow. C. chrysallis is about twice as high as S. callizonus and much more ventricose. Like S. crumenilla it has a swelling in the distal end of the last whorl in the umbilical region behind the peristome. The distance between parieto-angular lamella and palatal teeth is very narrow. S. bacca is distinctly higher, with more pointed apex. It has more whorls, but fewer ribs on the last whorl. Both palatal and columellar sides bear two teeth. S. glebula, although of about the same height as S. callizonus, has one whorl more. It carries two teeth on the columellar side and two one the palatal side. Of the latter two the lower tooth lies almost at the basal side. S. leucostolos is somehat larger than S. callizonus and the ribbing is weaker. It has a distinct swelling in the distal part of the last whorl in the umbilical region, whereas S. callizonus is not inflated in this spot.” (Benthem-Jutting, 1961)
Benthem-Jutting (1961) original descriptions on Sinoennea callizonus – “Shell ovoid-cylindrical, glassy transparent, shining. Top whorls smooth, the following ones ribbed with elegantly off-standing ribs, about 20 on the last whorl. There is no spiral striation. Whorls 6, regularly increasing in size. The 4th and 5th whorls are of almost equal width, the 6th whorl attenuating towards the base. Profile of each whorl convex, the greatest diameter somewhat above the middle, causing a certain “shouldering” of the whorls. Top a little pointed, base rounded. Umbilicus open, but not wide, not obscured by swelling of the distal part of the last whorl. Aperture almost vertical, quadrangular with rounded angles. Peristome continuous, adnate to the previous whorl, thickened, reflectedm with a strong parieto-angular lamella. Exerior margin receding near the angular sinus, then protruding in the middle, receding again towards the base, On the palatal side there are two teeth, of almost equal size The upper one lies at the edge of the peristome, the lwer one deeper in the throat. Columellar side with only one tooth, a rather strong plate, deep in the aperture. It corresponds with a shallow groove on the distal part of the exterior of the last whorl in the umbilical region.”
Sinoennea callizonus – “Dimensions: Height 2.3-2.8 mm; Width 1.4-1.5 mm; Height of aperture 0.9-1.1 mm.” (Benthem-Jutting, 1961)
Type locality – “Malaya; Gunong Sinyum, Pahang” (Benthem-Jutting, 1961)