308 THE DOLABELLINAE. 



Foot. — The ventral surface, or foot, passes uninterruptedly over into the 

 sides of the body and is uniformly smooth, save for contraction rugae in its 

 anterior and posterior portions. The anterior end of the foot is curved upward 

 and invaginated with the whole head-region. 



Epipodia. — The epipodia are thick and fleshy, scarcely mobile, and are 

 united behind the siphon at the upper side of the posterior disc for a distance 

 of 27 mm. They are short and low, with thick closely interlocking margins, 

 in front sloping rapidly downward to a low ridge-like fold, which terminates 

 just in front of the middle of the length of the animal. The anterior ends of 

 the epipodia are 4 mm. apart, but little more than the width of the genital 

 groove, which emerges between them. Inclosed within the low margins lies 

 a smooth flattened area of elongated oval shape, limited behind by the anterior 

 edge of the mantle. It is 28.7 mm. in length and 15.6 mm. in greatest width. 

 In Plate 1 this shows a light purple color, which also appears on the inner mar- 

 gins of the epipodia, and doubtless extends inward over the walls of the pallial 

 cavity to a greater or less extent. 



The closely appressed margins of the epipodia fit snugly together with 

 interlocking grooves and ridges, leaving an anterior opening for the inflow of 

 water, and a posterior rounded one, somewhat above the centre of the disc for 

 its exit. On reaching this posterior foramen, the inner thin edge of the epi- 

 podium curves over to the outside of the margin, and is prolonged around the 

 opening in an irregular curve on the face of the disc, receding from and approach- 

 ing the thickened edge of the opening in a number of sinuous bays. The bound- 

 ary of these bays is a low sharp-edged fold, averaging 1 mm. in height, and 

 incloses an area not appreciably different in its surface texture from the remainder 

 of the posterior disc. No trace of this is to be seen on Plate 1, nor have I found 

 anything similar in D. hasseltii. Its significance is unknown. 



The external spermatic groove appears from beneath the anterior end 

 of the mantle, and continues forward in the median line as a sharply defined 

 furrow with prominent margins. At the anterior end it diverges to the right 

 and enters the invaginated portion of the body in the preserved specimen. As 

 seen in Plate 1, in the living animal it curves forward and downward to the 

 right below the base of the right rhinophore, to the opening of the penis-sheath, 

 which it enters below the right tentacle. 



Pallial complex. — Separating the margins of the epipodia a roomy cavity is 

 disclosed, the mantle, covering the ctenidium, partially dividing it into an 

 upper and a lower chamber, which communicate widely at the right side. Iq 



