s'rri{(;K((N-i'iNiiKs. 



1049 



)!' the I'rmik- tlic cdracoid liniic (cr). and an inner anterior part, eor- 

 resjiDndinL;' to (lie |ireror:icoi(l (per). At tlie line \viici-<' 

 the seapulM ami coracoid meet (;it /'. r.s). the [jeetoral 

 tin is arli<'ulated, in the s;inie niannei' as nornially meets 

 US among tlie Teleosts; hut the articulary surface of the 

 large first ray (s])inous my) glides partly on a projec- 

 tion of tile elaxicle. an .-irtieulation that calls to nnnd 

 the pectnr;d tin of the ShcMfHsh. In the hasal structure 

 same, M flat, lieart-sluiped hone. Its origiiinl dermal of the tin we find (tig. I'SS) the same four radialiii 

 stnictiuv is indicated niereh li\ a siiudl, terete protii- (liracliial hones, /— /) as in the 'feleosts, increasing in 

 bertmce, e\fii externalh visilile, and it is a|i|iMreiitl\ length hackwards (do\vnw:u'<ls). But these are cartila- 

 to he reg:u-ded from ;i morpliologienl point of view iis ginous mid divided into two joints (;in iiuier and an 



outer row. ef. alio\(\ on the Herring, ]>. 951 ): and at 

 the hind inferi(n- margin of the fin there are se\ci'al 



ill ;i manner that reminds us es|)ei'ially 

 fishes (see ahoxe, y. (il9), hoth the chniele and the 

 iiiter<'l:i\icle are continued inwards 1)\ an entire osseous 

 disk. Inniiing the posterior w, -ill of the liraiiehial (•a\it\-. 

 Witliiii (al)ove) the anterior extremities of the inter- 

 clavicles, where these bones meet in the median line of 

 the hcUw N\(' tind, situated under the coiiiis (iiicridsus, 

 and forming, as it were, a special iirotectioii tor the 



{W(^t4 



Fig. 288. Ijeft pectoral tin of a male Sturgeon (Adpenser stiii'io) 



1,845 nun. lonu- and takon at Lulea on Jnly tfttti, 1893. ' ., of 



the nalviral size. Seen from above. 



/f, radiate of lite first (c-oniposile) ray, answering to (Jegenhaur's 



mesopteri/ijitwi : / — 4. tlie four true radialia, the last of wliicti (4) 



answers to Gegenbaur's metapteri/giiun. 



representing the sternum of the higher \ertehrates 

 (sternal sciife). 



The internal parts of the shoulder-girdle — omitting 

 the alread\- mentioned sujirascapular part (s.<c) — form 

 ii continuous mass of cartilage; but in adult Sturgeons 

 this mass is seen to consist of three several parts, the 

 same as we have seen above in Glanomorphs, Cyprino- 

 morplis, and Thrissoniorphs, namelv an upper part, an- 

 swering to the scapula (sc). a lower part, answering to 



Fig. 280. Left ventral tin and pelvic bone (>f tlio same Sturgeon as 

 in the preceding figure. ' ,, of the natural size. Seen from above. 



/or. foramen obturatoriuni (?): mtp. metapterygium : pil, processus 

 iliacus(?); /)/>. processus pubicus(?); 1 — 7, radialia. 



supplementary radialia, the inner ones branching <iff. 

 however, from the outermost (iiiiidmost) radiale, called 

 by Gegenbauh the nn-tdjitcrii'/iin)!. A similar, but still 

 greater superfluity of cartilaginous radialia apjiears in 

 the basal parts of the ventral fins (fig. 289). The num- 

 ber of radialia is greater in the Sterlet than in the 

 Sturgeon (fig. 289, / — 7), being in the former at least 

 9, in the latter 7; but in tlie foi-mer the first three, 

 in the latter the first four radialia (basalia) articu- 

 late at the proximal (iiuier) end with a common 

 cartilage, answering to the pelvic bone of the Tele- 



