EOLIS. 



EXPLANATION OF THE PLATES.* 



Plate 7. 



Fig. 1. General view of the viscera of r E. papillosa from above :—a, buccal mass; b, (Esophagus : 

 c, stomach; d, intestine; e, anal nipple; /, great central canal of the digestive system • 

 9, 9, 9, lateral branches of the same; h, ventricle of the heart; i, auricle; j, testicle; 

 k, k, portions of the gland for secreting the mucous envelope of the eggs ; I, I, ovarium ; 

 m, cerebral ganglions, with the nerves passing off from them; n, n, ganglions at the base 

 of the dorsal tentacles. 



2. Digestive apparatus of E. papillosa, with the glands of the papillae removed :— a, buccal 



mass ; b, b, corneous plates of the same ; c, oesophagus ; d, stomach ; e, intestine ; f, anus ; 

 g, great central canal leading from the stomach ; h, h, lateral branches leading from the 

 same to the papillae; i, ducts from the glands of the papillae. 



3. Digestive apparatus of E. olivacea ; the letters correspond with those of the previous figure. 



4. Digestive apparatus of E. coronata ; letters as before. 



5. View of the cavity of the buccal mass from above, the fulcrum being divided, and the horny 



plates, a, a, drawn apart :— b, b, cutting edge of the jaws ; c, inner lip ; d, fulcrum of the 

 horny plates ; e, anterior and posterior transverse muscles for closing and opening the 

 jaws; /, tongue; g, g, wedge-shaped muscular mass, or support of the same; h, h, 

 muscular cheek mass ; i, folds of the lining membrane of the mouth ; j, oesophagus. 



6. Lateral view of the buccal cavity and cheek mass, with a horny plate removed : — a, salivary 



gland ; b, inner lip ; c, interior of a horny plate ; d, cutting blade ; e, fulcrum ; /, anterior 

 and posterior transverse muscles for closing and opening the jaws; g, flattened upper 

 borders of the cheek mass ; h, spiny ridge of the tongue ; i, oesophagus. 



7. Two of- the transverse arched plates from the tongue of E. papillosa, much magnified to 



show the spines. 



8. A portion of the tongue of E, olivacea. 



9. Teeth from the tongue of E. nana. 



10. Upper aspect of three plates of the same. 



11. Tongue of E. alba. 



12. Upper aspect of three plates of the same. 



13. Stomach of E. papillosa laid open, showing the rugae of the internal surface of the bulb, 



central canal, and lateral branches. 



Plate 8. 



Fig. 1. General view of the vascular system, all the other viscera being removed: — a, ventricle 

 of the heart ; b, auricle ; c, c, c, portions of the pericardium cut across and laid back ; 

 d, aorta ; e, gastric artery ; /, great ovarian artery ; g, a branch of the same, supplying the 

 posterior portion of the foot ; h, the artery supplying the anterior portion of the organs 

 of generation; i, buccal artery; j, arterial branches going to the channel of the mouth 

 and anterior of the foot ; k, buccal mass ; I, I, large anterior veinous trunks passing from 

 the skin to the auricle ; m, large dorsal veinous trunk receiving veins from the skin, and 

 passing to the auricle. 

 Fig. 2. The organs of generation partially unravelled : — a, portion of the penis withdrawn ; 

 b, common female channel; c, c, testicle; cl, ovarium; e, e, oviduct; f, dilated portion of 

 the same ; g, g, great gland for secreting the mucous envelope of the eggs ; h, sack of 



* All the anatomical figures on these plates are from E. papillosa, unless otherwise stated. , 



