. British and Irish Salmonidæ. ra, while fromeither side a rib is dii-ecteddownwards. Fig. 8. Abdominal vertebra of salmon, c. centrum or body :na. neural arch : ns. neural spine: es. ejiipleural spine. The caridal vertebroD (fig. 7) are furnished superiorly with neural arches, (na)and spines (ns), but well developed transverse processes are absent, while alongthe lower surfaces of the bodies of each is a second or the hremal arch (ha) whichserves to protect blood vessels, while inferiorly from this arch springs a ha;malspine (hs). Along the median line of the body, between the neural or hcema
. British and Irish Salmonidæ. ra, while fromeither side a rib is dii-ecteddownwards. Fig. 8. Abdominal vertebra of salmon, c. centrum or body :na. neural arch : ns. neural spine: es. ejiipleural spine. The caridal vertebroD (fig. 7) are furnished superiorly with neural arches, (na)and spines (ns), but well developed transverse processes are absent, while alongthe lower surfaces of the bodies of each is a second or the hremal arch (ha) whichserves to protect blood vessels, while inferiorly from this arch springs a ha;malspine (hs). Along the median line of the body, between the neural or hcemal spinescertain vertically directed dagger-shaped bones are inserted, to which areattached the bases of the dorsal and the anal hindmost cau- dal vertebra, whichis of a small size, ar-ticulates posteriorlywith a fan-shapedbone, which alongwith the last few -yhasmal processes aresimilarly enlargedand flattened, andtermed hypuralbones (htj), whichsupport the mainportion of the caudalfin. The last twovertebree are gener-. ally counted as one,a course I shall fol-low, as in specimenswhen fresh or inspiiit it sometimesbecomes difficult todistinguish the lineof separation be-tween these twobones. The epipleu-ral in the embryonicstage is connectedwith the termina-tion of the noto-chord which liesbeneath. Fig. 9. Hind end of vertebral column of asalmon, ha. litemal arch : hs. ha>mal spines :hy. hypural bones : na. neural arch: ns. neuralspine. 24 (Os framicrse, Cuv.), Pterygoid. 25 {Pteryfinidien interne, Cuv.), Entopterygoid. 26 {.Tiigal,Cuv., Ihjpotympanic, Owen), Quadrate (Huxley). 27 (Tympanal, Cuv. Fretympanic, Owen),Metaptei-ygoid (Huxley). 28, Opercle. 29, Stylohyal. 30, Preopercle. 31 (Jilcsotympanic, Owen),Sympleotic. 32, Subopercle. 33, Interopercle. 34, Dentary. 35, Articular. 36, , Epihyal. 38, Ceratohyal. 39 and 40, Basihyal. 41 ( lingual, Cuv.) Glossohyal. 42 (Queuedc Vos liyoide, Cuv.), Urohyal. 43, Branchiostegal rays. 46 (Surscajyulaire, Cuv.
Size: 1847px × 1353px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, bookidbritishirish, bookyear1887
