BULL. U. S. B. F. 1912. 



PLATE LXI. 



GILL FILAMENTS OF 4TH ARCH 



HEAD OF KIDNEY 



ESOPHAGUS 



OPBRCULUM 



PREOPERCULUM 



CHEEK MUSCLE IN SECTION 



ORAL MEMBRANE 



4TH BRANCHIAL ARCH 



....3RD BRANCHIAL ARCH 



2ND BRANCHIAL ARCH 



ST BRANCHIAL ARCH 



HVOID CORNi: 



FIG. 15. Composite picture of lateral and longitudinal distribution of normal thyroid in the Salmon idsie, with vessels. 



1ST COPULA (CARTILAGE) 

 1ST BASI BRANCHIAL 



2ND BASIBRANCHIAL 



ORAL MEMBRANE 



TEETH OF TONGUE 



BASIHYAL 



TONGUE c RTIL'AGE 

 H OH'YAL 



MUSCLE 



2ND COPULA (CARTILAGE) 



4TH BASIBRANCHIAL 

 3RD BASIBRANCHIAL 



3RD COPULA (CARTILAGE) 



: " -|--. VENOUS SINUS 



; . .{-MUSCLE 



ESOPHAGEAL MUCOSA 



AND:AREOLAR TISSUE 



HYPOHYAI, SYMPHYSIS 

 MUSCLE 



AURICLE 



BULBUS AORTAE 

 .VENTRICLE 



.'EPITHELIUM 



SUBMUCOSA 



SYMPHYSIS OF CLAVICLE CORACOID PAIRS 

 VENTRAL AORTA 

 UROHYAL 



BRANCHIAL SPACE 

 FIG. 16. longitudinal and dorso-ventrnl distribution of thyroid in the SalmoimUe. 



