OEsophagus (fig. 1 c).—The buccal mass narrows into the œsophagus, which passes through the nerve-collar and peri-œsophageal cartilaginous ring, and is continued to the stomach without ingluvial dilatation. It dilates slightly as it enters the stomach. Stomach (fig. 1 m).—The stomach is saccular and thick-walled. It shows two slight constrictions. The walls present on their inner surface strong longitudinal plicæ, which are prolonged into the intestine, and continue throughout its length. Lying within the stomach is a loose tunic or sac with thick, though almost transparent, walls, showing longitudinal plicæ or corrugations. It has a wide orifice at one end, and at the other is thin or open. I have not been able to discover that it has any organic connection with the walls of the stomach, but as I have found it in all the specimens I have examined, I do not think its occurrence can be accidental. The pyloric opening is at the lower end of the stomach and close to the cardiac opening. The commencement of the intestine is shown by a well-marked constriction. Neither cardiac nor pyloric opening is protected by a valve. Pyloric cœcum (fig. 1 n).—Immediately following the constriction there is given off a long cœcal dilatation with thin but tough transparent walls. It expands at its attached end and tapers gradually to its opposite rounded extremity. When in sitû it forms a half curve round the stomach. As will be presently noticed, the hepatic ducts open into this cœcum. On the broadest part of its wall, at the attached end is a circular coat formed by a radiating mass, whose nature I have not discovered. Intestine (fig. 1 h).—From the pyloric cœcum the intestine narrows gradually until the anus is reached. At somewhat less than half the distance between the cœcum and the anus it is folded over so as to form a distinct flexure. The anus has two stalked and leaf-like lateral valves. Ink-sac (fig. 1 h).—The ink-sac is large and broad. Its highest and broadest part lies near the intestinal flexure, and from this part it narrows to its opening into the anus. Its coat is silvery and, in places, iridescent; and the dark sepia shows through the sac-walls. Throughout its length it is held closely to the intestine by a membrane. Liver (fig. 1 f).—The liver is large, extending from immediately above the cephalic cartilage for about two-thirds of the length of the œsophagus. It is encased in a capsule showing under the miscroscope close fibres and yellow concretions. The liver itself is loose, and under the microscope shows clustered follicles and interlacing tubes with abundant yellow concretions. The bilobed condition is not observable.