THE DEIiMAL FIN-RAYS OF FISHES. 517 



40. VoGT, C. — ' Embryologie des Salmones,' Neuchatel, 18i2. 



41. Whiteaves, J. F. — "Illustrations of the Tossil Tishes of the Devonian 



Rocks," 'Trans. E,oy. Soc. Canada,' vol. iv, 1887, and vol. vi, 1888. 



42. Woodward, A. S. — ' Cat. Fossil Fishes of the British Museum,' vols. 



i— iv, London, 1889—1901. 



43. Woodward, A. S. — 'Vertebrate Palaeontology,' Cambridge, 1898. 



EXPLANATION OF PLATES 35—41, 



Illustrating Mr. Edwin S. Goodricli's paper '^On the Dermal 

 Fin-rays of Fishes — Living and Extinct." 



List of Reference Letters. 



JcL Actinotricliia. d. c. Bone cell. b. in. Basement membrane, b. s. Bony 

 segment. ^. sc. Body-scale, c. Canal, c;^^. Connective tissue, c. 5. Cut sur- 

 face, c^. Ceratotrichia. rf. Denticle. ^.<?. Distal cartilage, ^/z's^.^s. Distal seg- 

 ment of dermal ray. d. r. Distal region of dermal ray. cl, s. e. Distal segment 

 of endo-skeletal ray, exposed, e./. Edge of fin. e./. r. Endo-skeletal fin-ray. 

 ep. Epidermis, fulc. Fulcral scale, g. r. External layer of ganoine. hi/p. 

 Hypural cartilage or bone, i.b.r. Inner bony region, i.f.r. Inner fibrous 

 region, iptm. Inner pterygial muscles, i.r. Inner region, i.s.s. Impression 

 of superficial scale, j. Joint, kpt. Kamptotrichia. lept. Lepidotrichia. 

 lig. Ligament, m. Stony matrix, ms. Muscle, m.sc. Median scale, n. 

 Nucleus, nt. Notochord. o.b.r. Outer bony region, op. External opening 

 of bone canal, optm. Outer pterygial muscles, o. r. Outer region, p. r. 

 Proximal region, pr.s. Proximal segment, sc. Scale, sk. Skin, sm.sc. 

 Small scales overlying dermal rays. s. s. Superficial scale. 



PLATE 35. 



Fig. I. — Portion of the first dorsal fin of Scy Ilium cauicula cut off and 

 dissected on the left side so as to show the relations the skin, muscles, 

 dermal rays, and endo-skeletal rays bear to each other. Slightly diagrammatic 

 and enlarged. 



Fig. 2. — Similar view of a portion of tlie dorsal fin of Acipenser sturio. 



Fig. 3. — Similar view of a portion of the ventral region of the caudal fiu 

 of Ceratodus Forsteri. 



