under the shield. The occurrence of this internal shell was known to Pliny the Elder; the shell was used by the ancient physicians for the sake of its carbonate of lime. The calcitic shell is situated beneath the hinder part of the shield, and is perceptible through the skin. The color of the shell is whitish. The shape of the shell is oblong-oval and thin, slightly convex above, and correspondingly concave beneath, with a membranous margin. The apex or nucleus is at the posterior margin but inclined towards the left side, and forming the apophysis by which the shell is organically attached to the animal. The length of the shell is 13 mm (1/2 inch) and the width of the shell is 7 mm (1/4 inch). Shells of different Limacidae species are undiagnostic: in other words, they are not helpful for identification purpose. Digestive system: The formula of the radula is: 62-73/ × 138–157. The intestine has six convolutions and is without a caecum. Of the six convolutions of the intestine, four are imbedded in the liver, and two hang freely in the body cavity. The nervous system is composed of the typical ganglia. The pedal ganglia are placed beneath the radula sac and joined by an anterior and a posterior commissure. The abdominal ganglion lies a little to the right of the median line. The visceral ganglia occupy the angle between the lingual sheath and the oesophagus and the buccal ganglia are widely separated but joined by a commissure nearly as thick as the ganglia themselves. Reproductive system: The hermaphrodite gland (HG) is elongated and large, and is connected with spermoviduct (SO) by means of the hermaphrodite duct (HD) which takes its course through a portion of the albumen gland (AG). The spermoviduct is thick and well convoluted, and separates further down into a vas deferens or sperm-duct (VD) and an oviduct (OV). The former opens into the upper end of a very long penis (P), to which a strong retractor muscle (PRM) is attached. The lower portion of the penis unites with that of the oviduct at the genital orifice, so that there is no vestibule. The receptaculum seminis (RS) opens into the lower end of the penis near the junction of the two ducts. Distribution Fossil distribution The internal shells of the different species of Limacidae are not recognizable to the species level. Therefore, the fossil distribution