214 Records of the Indian Museum. [Vol. VIII, 



form a network with connective tissue fibres similar to that in the 

 mantle-wall. 



//. Pallial Complex. 



The pallial complex is a more or less circular area under- 

 lying the mantle, the centre corresponding to a point a little be- 

 hind the anterior one-fourth of the body-length. It extends equally 

 on each side to the junction of the mantle with the base of the 

 foot. The pulmonary chamber lies on the right side of the animal 

 and occupies about one-third the area of the pallial complex. The 

 roof of the pulmonary chamber is fused with the under surface of 

 the mantle, and the floor is continuous with that of the pallial com- 

 plex. The pulmonary aperture (?) is situated at the right antero- 

 lateral corner in the same transverse line with the anterior end of 

 the pericardium. 



The pericardium lies in the right anterior quadrant of the 

 pallial complex, forming a prominence on the surface of the body 

 on the right side (mentioned in the description of the external 

 characters). The pericardium is a broad oval sac having the heart 

 obliquely placed inside it. The roof of the pericardium is fused 

 with that of the pallium, while the floor is continuous with that of 

 the latter also. 



The heart is placed obliquely in the pericardium and extends 

 from near the centre towards the right antero-lateral corner of the 

 pulmonary area. The ventricle lies in front of the auricle. It is 

 a thick-walled sac, wider than it is long. The origin of the aorta 

 is directed anteriorly, and to the right. The pulmonary artery lies 

 along the right border of the kidney in its posterior half. 



The kidney occupies the left half of the pulmonary area. 

 It forms a flattened hatchet-shaped body, with the two corners 

 prolonged along the margin of the pulmonary area towards the 

 right border of the same. It is adherent to the under surface of 

 the mantle above and to the floor of the pulmonary area below, 

 and lies over the salivary glands and the anterior end of the liver. 

 The organ is thick in the centre and is thinned out at the margin. 

 There is no distinct ureter; the kidney seems to open directly 

 into the pulmonary chamber close to the pulmonary aperture. 

 The tissue of the kidney has a spongy appearance; it consists 

 of long wavy tubules held together Ijy loose connective tissue. 



The female genital aperture lies on the anterior aspect of the 

 pulmonary area; the anus lies anteriorly to, and on the outer 

 aspect of the female genital aperture. 



///. Digestive System. 



There is a large protrusible proboscis. In the larger of the 

 two specimens obtained, the proboscis was everted to its full 

 extent. It is a hollow, thin-walled cylindrical body, with the 

 mouth of the animal forming a triradiate aperture in the centre 

 of the blunt rounded tip. The base of the proboscis is attached to 



