450 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
15. A CONTRIBUTION TO OUR KNOWLEDGE OF THE MORPHOLOGY OF LAMELLLBRANCHIATE 
MOLLUSKS. 
Page. 
Adductor and retractor muscles 391-393 
Andrews, E. A 389 
Branchial chambers, conclusions from acomparison of .426-427 
Br oks, W. K 389 
Byssus 395-396 
Changes in structure brought about by the degeneration 
of the foot 425 
Crystalline style 402-403 
Detailed str cture of the gills 414-422 
Digestive tract 400-403 
Excretory organ 409-411 
Explanation of plates 430-436 
Foot 393-395 
General conclusions in regard to the gills 424 
General considerations 425-428 
Generative mass 404-406 
Gill of Ostrea virginiana 422-423 
Gill of Pecten irradians 420-422 
Gill of Venus mercenaria 422 
Gill of Yoldia 414-418 
Gill of Yoldia, contractions 414-415 
Gill of Yoldia collection of food 415 
Page. 
Gill of Yoldia, structure 415-418 
Gills 411-414 
Gills of Area pexata 419-420 
Gills of Solenomya 418-419 
Intestine 402 
Liver 403-404 
Mantle 396-397 
McDonald, Marshall 389 
Mouth 400 
Muscle system of Mytilus 425-426 
Nervous system 411 
(Esophagus 401 
Palps 400-401 
Papers cited, list of 429 
Pelseneer, Paul 389 
Phylogeny of the gills 427-428 
Shell 390-391 
Siphonal region of the mantle 397-400 
Stomach 402 
Vascular system 406-409 
Wilson, H. V 389 
o 
