PLATE XXXIX. 



Fig. 1. — M eg alatr actus aruanus, Linn. Blood sj'stem. 



Fig. 2. — M. aruanus, Linn. Stomach. 



Fig. 3. — M. aruamts, Linn. A section through the anterior part 

 of the visceral coil. 



Fig. 4. — .1/ aruanus, Linn. Auricle, ventricle and fused portion 

 of the aortse, cut through the centre and laid back. 



Fig. 5. — M. aruanus, Linn. Anterior view of body proper. 



Fig. 6. — M. tnaximus, Tryon. Organs in the body cavity. 



Fig. 7. — M. maximus, Tryon. Operculum. 



For explanation of letters, see p. 450. 



