1906.] ANATOMY OF CEXTROPHOKUS CALCEUS. 885 



Fig. 3. The alimeiitaiy tract and associated glands. A, B, C, D, E, parts of 

 pancreas; B.D., bile-duct with arteries and veins; C.A., cujliac artery; 

 CAR., cardiac portion of stomach ; DUO., duodenum ; H.V., hepatic vein ; 

 L.M., lieno-mesenteric artery ; PY., p,yloric portion of stomach ; S. 1, large 

 spleen; S. 2, small spleen; S.V.I., spiral-valve intestine; V., ventricle; 

 VE., vein running from middle lobe of pancreas to bile-duct. (For other 

 letters, see text.) 

 3 a. Pancreas viewed from other side. 



Plate LVIII. 



Centrophorus calceus. 



Fig. 4. The afferent arches. The ventricle has been turned forward somewhat to 



expose the sinus venosus. D.C, opening of the Cuvierian duct into the 



sinus venosus ; H., opening of hepatic vein into sinus venosus ; L.F., 



labial folds; S., subclavian vein ; S.A., sinu-auricular aj)erture. 



5. The efferent arches. C.C., common carotid; F].C., external carotid; 



I.e., internal carotid; S., spiracular cleft. 

 (3. Suspensorial apparatus of jaws. CH., cerato-hyal ; H.Y., hyomandibular ; 

 L.C., three labial cartilages of right side ; L.J., lower jaw ; L.P., large 

 process in connection with upper jaw (well seen in fig. 16, P.) ; L. 1, liga- 

 ment connecting hyomandibular to upper jaw ; L. 2, large ligament 

 connecting hj'omandibular to lower jaw ; L. 3, ligament connecting upper 

 and lower jaws; M., muscle in connection with two upper labial 

 cartilages ; P.O., three pre-spiracular cartilages in anterior wall of spiracular 

 cleft ; S.C., spiracular cleft. 



7. Trunk-vertebraj in intra- and inter- vertebral section and in side-view. 



E.L., elastic ligament. 



8. Anterior caudal vertebra in intra-vertebral section. A.M., attached muscle; 



A.P.N., aperture for spinal nerve; C, calcified region; C.A., caudal 

 artery ; C.V., caudal vein ; E.L., elastic ligament. 



Plate LIX. 



CeiitropJiorus calceus. 

 Fig. 9. Skeleton of the anterior dorsal fin. 



10. Skeleton of the posterior dorsal and caudal fins. 



11. Dorsal aspect of the skeleton of the right pectoral fin. B., basal cartilage; 



C, ceratotrichia attached to bases of D.R. ; C.P., articular process ot 

 pectoral girdle ; D.R., distal radialia ; P.R., proximal radialia. 



12. Ventral view of the skeleton of the right pelvic fin. B., basal cartilage ; 



P.P., articular process of pelvic girdle. 



PlATE LX. 



CentropJiorus calceus. 

 Fig. 13. The urinary system. C.U., common ureter; D.A., dorsal aorta; J.U. 

 junction of ureters ; K., kidney ; K.A., anterior extremity of kidney ; 

 K.D., kidnej^-duct ; M., myotomes cut across ; P.C.S., position of the 

 posterior cardinal sinus (peritoneum removed) ; S.D., ducts openino- into 

 ureter from kidney ; U.O., ureter opening on urinary papilla (bisected) in 

 cloacal cavity. 



14. Dissection of the 9th and 10th cranial, occipito-spinal, and brachio-spinal 



nerves. B.P., brachial plexus; D.B.X., small branches from L.L.B.X. 

 supplying dorsal muscles ; L.L.B.X., lateral-line branch of vao-us ; 

 M.L.J., branches of occipito-spinal nerves to muscles of lower jaw- 

 S.C., spiracular cleft; V.B.X., visceral branch of vagus. 



15. Dissection of the brain and cranial nerves viewed from the dorsal surface. 



A.V., aquaiductus vestibuli of ear; A.V.C., anterior vertical canal of ear • 

 H.C., horizontal canal of ear ; L.L.B.X., lateral-line branch of the va"-us • 

 O.C, olfactory capsiile; P., large process attached to upper jaw; P.V.C.' 

 posterior vertical canal of ear; U., utriculus of ear; V.B.X., visceral branch 

 of vagus; X., vagus nerve. 



PXATE LXI. 



Centroplwrus calceus. 

 Fig. 16. Dissection of the cranial nerves in the left orbital region. B.V. blood- 

 vessel running parallel with the inferior rectus muscle; CM.,' cavity 

 lodging muscle (M.2 in fig. 17); C.T.VIL, chorda tympani of facialis; 

 E.M.VII., external mandibular of facialis; EX.C, anterior branch of 



