98 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



unpigmented. Lateral areas of sole sometimes faintly mottled* 

 but not the central area. 



Head and Neck having a darkly pigmented band on each 

 side. A pair of- dorsal grooves is present on the neck, but no 

 vertical facial grooves occur on the front of the head, which is 

 covered with very small rugse. A well-marked oblique lateral 

 groove occurs on each side, the genital opening being on the right 

 lateral groove on the side of the head, about 1'75 mm. from the 

 right upper tentacle. Labial palps rather large. 



Pallial Lobes well developed, slightly granular, and spotted 

 with small patches of dark pigment. Shell-lobes wide and rounded, 

 but rather widely separated from each other, the right being about 

 4 mm, long and almost the same breadth (in alcohol, but probably 

 larger in life), and the left being somewhat smaller. Body-lobes 

 broad, the left extending uninterruptedly from the respiratory 

 opening to a little behind the base of the left shell-lobe, and 

 attaining a remarkable breadth over the animal's neck, which it 

 covers more or less completely. 



Dorsal Skin lining the shell translucent and colourless over the 

 lung, kidney, and pericardium, excepting for a trace of brown 

 pigment over the front end of the kidney, but mainly opaque 

 white over the upper part and left side of the liver and adjacent 

 organs, though showing some irregular translucent patches, 

 through which the dark liver is visible. 



Lung short, broad near the mantle-edge, but becoming 

 narrower behind, the upper edge receding from the suture. Roof 

 of lung richly vascular, a little more so even than in H. gomesianus. 

 Main pulmonary vein receiving numerous branches just in front 

 of the kidney, and a large branch from the left side of the lung as 

 it enters the pericardium. The largest of the afierent veins is 

 situated in front of this branch. A much smaller branched vein, 

 from the lower surface of the kidney, also unites with the main 

 pulmonary vein close to the heart. Numerous short veins cross 

 the narrow area to the right of the kidney, and can be clearly 

 seen from the outside through the roof of the lung. 



Heart large, the auricle being larger than the ventricle. 



Aorta dividing into two vessels just after leaving the 

 pericardium. The posterior passes backwards and supplies blood 

 to the liver, etc. ; the anterior, which is the larger, bends round the 

 intestine and a small part of the anterior division of the liver, 

 and passes forwards to the ventral ganglia, giving ofi on the way 

 a branch on the left to the salivary glands, and one on the right 

 to the body-wall immediately below the anus. 



Kidney sigmurethrous, tkick and rather narrow, though 

 broadening somewhat at the posterior end ; about 6 mm. long, 

 and extending about 2 mm. in front of the heart ; containing very 

 numerous folds of a brown colour, Primary ureter very broad 



