GENEEAL INDEX. 



Page 



" Epidermis " 500 



Increase of the thickness of the shell 500 



Nacre or mother-of-pearl 501 



Formation of pearls adherent to shell 501 



detached globular pearls 501 



Progressive displacement of adductor muscle 501 



SlPHONIFEROUS CONCHIFERA 502 



Uses of the siphons 502 



Family of " Borers," Pholas, Teredo, &c 504 



Nervous system 504 



in the T>imyaria 501 



Monomyaria 504 



" Ocular points " around the mantle of Pecten 504 



" Auditory sacculus " in Cyclas cornea 505 



Generative system of the Conchifera 505 



Ovaria 505 



Organ of Bo j anus .... 506 



Oviposition 507 



Transfer of ova to the branchial laminse . ... 508 



CHAPTER XXI. 

 BRACHIOPODA (Cuv.) ; PALLIOBRANCHIATA (OWEN). 



BRACIIIOPODA General characters of the class 509 



Shells 509 



Muscular system 510 



Mantle 510 



Mouth 510 



Mechanism of the arms 511 



in Terebratula psittacea 511 



Terebratula Chilensis 511 



Use of the arms in procuring food 512 



Alimentary system in the Brachiopoda 512 



Respiratory structure of mantle 513 



Circulatory system 513 



Nervous system 516 



Organs of sense 516 



Reproductive organs 516 



CHAPTER XXII. 



GASTEROPODA. 



GASTEROPODA General characters of the class 518 



Formation of shells 519 



Anatomy of the Snail 523 



Muscular envelope 523 



"Foot" . . 523 



Tentacula 523 



Dental apparatus of the mouth 524 



Tongue 524 



Alimentary canal 524 



Salivary glands 524 



Liver 524 



Respiratory cavity 525 



Circulation of the blood 525 



Slime-glands of the integument 525 



" Secerning organ of the viscosity " 525 



" Sacculus calcareus " 526 



Hermaphroditism of the Snail 527 



