160 Transactions. — Zoology. 



working the odontophore, are shown in fig. 2 (ab) ; they end in 

 two globular-euded rods. 



Alimentary System. — The mouth is situated on the lower sur- 

 face at the anterior end of the body ; it is simply an oval-shaped 

 sucking-disc, and has a serrated appearance. It opens into a 

 large oesophagus, surrounded by strong muscles ; in it lies the 

 odontophore with its three coils lying on the left side of the 

 body when examined from below (shown fig. 2, de). I have not 

 been able to distinguish clearly an enlarged part, representing 

 the stomach. The intestine has a great number of coils. I 

 have traced them all out; they are shown in fig. 4 {a to b). The 

 coils difi^er from those in the European P. vulf/ata. The rectum 

 is slightly swollen, and the anus opens on the left side of the 

 head, under the mantle (shown k, fig. 3, and b, fig. 4). The liver 

 is very large, occupying nearly the whole of the body cavity ; it 

 covers the whole of the intestines (shown fig. 2, xy, and fig. 3, 



fg)- 



I have not been able to make out the salivary glands referred 

 to by Professor Kay Lankester in the " Annals of Natm-al 

 History." 



EXPLANATION OF PLATE XI. 



Fig. 1. Eepresents the animal, seen from below ; ab, the foot ; c, mouth ; 

 de, fringe of the mantle round the shell ; fg, branchia). 



Fig. 2. A drawing of the animal after removing the foot ; ab, muscles 

 round the head ; de, odontophore (ui situ) ; /, g, h, k, parts of 

 the intestines ; pq, circular muscle ; hn, ovary ; st, free fringe 

 of the mantle ; xy, liver, filling up the interspaces. 



Fig. 3. A di'awing of the animal after removing the shell and outer cover- 

 ings, seen from above ; abc, coils of the intestine ; d, anal 

 end ; e, oral end ; fg, liver ; pq, circular muscle ; Im, mantle ; 

 xy, nerve commissure. 



These three figures are enlarged six times. 



Fig. 4. The coils of the intestines, magnified about eight times ; rt, oral end; 

 b, anal end. 



Fig. 5. Bepresents the nervous system ; ab, are pedal ganglia ; cd, the 

 parieto-splanchnic ganglia; ef, cerebral ganglia; /;, /(', pedal 

 nerves ; k, k', nerves of somatic cavity ; g, nerve going to the 

 intestines. 



