EXPLANATION OF THE PLATES. 391 

 Fi &' 



7. Terminal part (magnified seven times), of the pe- 

 duncle of an elongated specimen of Scalpellum ml- 

 gare, slit open, with the corium removed, showing 

 the two cement-ducts {a a), and a row of circular 

 patches (bb) of cement, by which the peduncle, 

 along its rostral edge, is attached to the thin horny 

 branches of the coralline. The larval antennae 

 are seen at the terminal point, and the two 

 cement-ducts can be traced into them. 



TAB. X. 



Figures all greatly 'magnified. 



1 . Mandibles of Follicipes mitella : exhibiting the upper 



(a) and lower (b) articulations, and 

 the three principal muscles; the 

 short upper cut off muscle runs to 

 its attachment at the base of the 

 palpus. 



2. ,, Lithotrya dorsalis, exhibiting four {act) 



roughened, thin, ligamentous apo- 

 demes for the attachment of the 

 muscles. 



3. ,, Scalpellum Fero?iii. 



4. ,, Ibla Cumingii. 



5. ,, Lepas anatifera. 



6. Palpus of Lepas anatifera. 



7. ,, Pollicipes mitella. 



8. ., Alepas cornuta. 



9. Maxilla of Lepas anatifera. 



10. „ Litliotrya dor sails, exhibiting the horny, 



rigid apodeme {a) buried in muscles, 

 together with the two other principal 

 bundles of muscles. 



11. ,, Ibla Cumingii. 



