Two Australian Land Snails. 225 



The salivary glands -.wv two peai--sliaped ln)dies. lying one on 

 either side of the alinKutary canal, just at the beginning of tlie 

 stoniacli ; they unite in the midline dorsally; from each a duct runs 

 forwards to open into the pharynx, just beside the oesophagus. 



The liver forms most of the visceral mass. One of its ducts is 

 seen in Plate XVII.. Fig. VII. 



The Nervous System, 



The cerebrial ganglia arc two oval bodies, lying on the dorsal 

 surface of the anterioi- jiart of the oesophagus; they are connected 

 in the centre so as to form a band across the alimentary canal. 

 From them two connectives run round each side of the oesophagus 

 to the sub-oesophageal ganglia. Large nerves are given off to the 

 tentacles, both superior and inferior, and one large nerve to the 

 little glandular structure near the inferior tentacle. 



The sub-oesophageal ganglia consist of the pedal ganglia, from 

 which nerves pass to the foot, and the visceropleural ganglia from 

 which nerves pass to the viscera and the body-wall. 



The eyes do not differ from the ordinary pulmonate type. They 

 are situated a little to the back of the top of the tentacle. In Plate 

 XV., Fig. I., this is not clearly shown, owing to the position of the 

 head, but it may be better seen in Fig. III. 



The inferior tentacle, as has been mentioned above, has a little 

 glandular structure with an opening at its base. This structure 

 seems different in the two species. In /'. compacfa it seems to form 

 a little pit on the top of a papilla, while in P. atramentaria it has 

 the foim of a little papilla with a groove on its under surface; but 

 I have not examined the structure in the living P. atramentaria. 

 In sections the glands are composed of the same forms of cells, and 

 in each species there is a large amount of dark staining material, 

 probably mucus, present. In P. compacta, however, the gland is 

 not nearly so definite, and seems to lie more in the cephalic wall 

 than in P. atramentaria. This may be clearly seen on comparing 

 Figs. IV. and V. in Plate XV. Woodward has noted the very pro- 

 minent " labial tentacles '' of Nanina caffra. He says they are 

 extremely sensitive, and " probably tactile in function, 1)ut not 

 used for prehesion as suggested for Glandina .'^ 



I can make no definite assertion as to the function of these struc- 

 tuies; they are certainly glandular, and as they are present on 

 carnivorous snails, I think they must have some use in either the 

 capture or killing of tlicir prey. 



The pedal gland teseml)les those described by Mr. Collinge for 

 /'. hochstetteri and /'. edn-ardi. It is greatly developed and folded 



