1068 



SCANDINAVIAN I-ISIIIvS. 



ii coalescence of tlic aiiieiMur |i;irt of the spiiinl cdliimn their piistorhital ijitdh) and in-cdrltital (;*/'///) |ii'<icc>;ses, 



similar Id that jnst inentioiiefl, and are withont rihs. , (4) an cthnjdidal region, aronnd the nasal cajisules (jY) 



The rii)s dt' tlie l',lasniol)ranchs, iiowever. diffei- essen- I Avitii the internasal cartilage, and lastly (o) a rostral 



tially froni those "I' the Tiledsts in being nmre deei)l}- regidii, with the cuntlnent tojis nf the pi-iniordial tra- 



<Mnl)ed(led in the nniscnlalure (Hesh), sd that they are heeiihe (the liasitraheenlar ti|i, //) and the sni»[)ortin" 



not innnediatelv ajiplied to tlic' )ieritdnenni, init in this cartilage {Ir) of the strongly de\elojied rostral system 



respect more nearh" answer to the scleral hones of the of the lateral line. 



Teleosts and the ribs of tiie higher ■ve'rtebrates. ' The occipital region is the shortest. In the nid.sf 



The sknll t'orms a continuons cajisnle of cartilage. priniitixe foians the anterior end of the ndtochord ex- 



with no dther limits between the separate parts than tends into the basidccijiital })art", and the foremost 



those indicated b\' the sitnation of the organs of sense nenra|)dpliyses <'nter into the cerebi-al capsnle. In the 



and by the oritices of tlie cranial nerves. With their j Sharks the articulation between the head and the first 



aid we can distingiush (/) an occipital region, aroiuid j vertebra is commonly very little more de\eloped than 



/■''•■. 



il'f -^^ 



ha ih 



Fig. 296. First dors.il tin with its skeletal piirts and tlie siibjaeent part of the spinal eclinini in a Cycluspundyle (Hasse), a Oreenlanil 

 Slinrk (A,;intln,rhiiias carcliarkis), 230 em. long, from the Nortli Sea. ' ., of the natnral size. 



b, hasal disk of the dorsal tin; ikt, rudimentary dor.sal spine, liidden under the skin; /i, dorsal tin uith its hunches of tihrils; c, and r,, tirst 

 (proximal) and second (distal) rows of radialia; cr, lateral ridge of the basal disk, a projecting crest for the attachment of muscles; Ig, ver- 

 tical ligament of the dorsal tin; le, elastic ligament of the spinal column; in, intemeural cartilages (intercalaria neuralia); na, nevirapophyses ; 



c. vertel)r:e, superficially constricted and each containing in the space between the constrictions a division of the spinal cord; dispondylic. 



each vertebra answering to two neurapophyses ; li, ha^nal ridge, divided into haemapophyses (ha) and interhannal cartilages 



{ih, intercalaria Im iiialia). 



the foramen magnum (figs. "298 and 299, ftim), and 

 limited in front by the nerrus riir/i(s firamen (vag), 

 (,?) a temporal or labyrinthine region, bounded in front 

 by the true trigeminal foramen (figs. 294 and oUO, tr), 

 (5) a frontal ((orbital) region, surrounding tlie orbits with 



in the Teleosts; but in the liays (fig. ;^)U0) and the 

 Ohima^ras (tig. 294), as well as in .some Sharks (fig. 

 298, and tig. 299), this articulation is accomplished 

 by trtie condyles (ore), in the same manner as in the 

 hiirher vertebrates. In the (/himu'ras, these condyles. 



" See, for example, Chlumi/dosdache in G..m:m.\x (Bull. Mns. Com]!. Zool. Harv. Coll.. vol. XII, No. 1), jil. VII. Hg. B. 



i 



