332 Olive B. Davies: 



those described by Professor Tate. The two living specimens 

 were pale grey, with two short darker lines on either side of 

 the posterior end of the foot, and on the dorsal surface of the 

 shield a few bright violet spots. At the posterior end the foot is 

 divided into three lobes, where the mucous pore is situated, and 

 from this a pedal groove runs along either side of the foot to 

 the anterior end. The whole of the imder-surface of these 

 grooves is ciliated, the cilia extending right round the surface 

 of the foot. (Figs. 5 to 12.) The pulmonary opening cuts well 

 into the edge of the shield ; the reproductive opening is situ- 

 ated just below the right superior tentacle, and slightly posterior 

 to it. There is no trace of a shell. The alimentary canal, liver, 

 kidney, heart, and some of the reproductive organs are all drawn 

 up, forming a visceral hump beneath the shield ; none of the 

 organs extending to the posterior end of the foot, as in the 

 Limacidae. I took the following measurements from a living 

 specimen: — Length of foot, 19.5 mm.; length of shield, 16.7 

 mm. ; depth of shield, 3.75 mm. The dorsal wall of the hump is 

 thick ; the anterior portion, being very vascular, forms the- 

 respiratory organ, while the sides of the under wall at its pos- 

 terior end are very thin, the organs being slightly visible 

 through it. 



Oi^gans of the Mantle Cavity. 



The heart occupies the left ventral corner of the mantle- 

 cavity, being covered dorsally and on the right side by the 

 kidney. The ventrice (Figs. 4, 7, 8) is oval in shape, and has 

 numerous muscles running in every direction through its walls. 

 The auricle (Fig, 6) is much smaller than the ventricle, and 

 very slightly muscular. The pericardium (Figs. 4, 6, 7, 8) 

 lies close to the heart, except on the left side, where it is 

 nearer the bodv wall, and on the right side at the region of the 

 reno-pericardial opening (Fig. 4). It is a delicate, but very 

 definite membrane, the nuclei in its cells showing up very 

 plainly in sections. I was unable to determine the course of the 

 blood vessels, excepting the main ones, which do not seem to 

 differ, at all from those of other forms. One vessel (Fig. 4) runs 

 up from the ventricle through the reno-pericardial canal. 



