ICLAS.MolilfA.MU.s. 



KKi.") 



A iind lill.")) ucNcT t'urms ;i clused ;ircli, l)Ul ciiil\- n and the aiMnieiirosis of tlic lateral iimsclcs, in the sanie 



veiitrally i^itiiated half'-^irch (in cadi side, tiie twn liahcs manner as tlie suin-aseapiilar eartilaiie suspends the 



being nsuaily emilhieiit in ihe median line nt' the li(diy, sh(ini(h'r-t;irdle in tliose fishes and in tlie Sharks. A 



hut in the Cinnueras nnited (inly by a mobile syni- j eloser nioi'])hologieal connexion in resjjeet to tiie strue- 



iiliysis. The main part of the pelvic girdle — originalK' ' tnre of the shoulder-girdle and pelvis exists, as we see, 



produced b\- the inward gi'owth and coaleseerK'e of the 

 inner (proximal) parts of the primary ventral radialia 

 answers to the ussa piiliis: and oftsa ii^rhii of the higher 

 vertebrates, but in most cases there aiJiiears on each 



between the Mlasmobranc-hs and the higher Ncrtebrates 

 than between the formei- and the Teleosts. 



The structure of the fnis points to a similar con- 

 clusion. In this i'esi>eet. it is true, the l'>lasmobranchs 



side a process ascending from the end of the pehic a|i|iroach nearer to the t'oninion [larent-fonns, where 

 disk, esjiecialh' well de\eloped in the l!a\s, and re]ire- all the lins were more or less diflerentiated sections of 



iktd H 



^ L 



''■, X 



tj) Ol)t tli ti 



(u f-^ 



n '"I 



'», ^ . _,/^ 



^' dp ^ 



Imi i chy op 

 bhy 



--// 



^'- 





, - mh 



n 



Fig. 294. .\utcri(.r j.art i.f tin 



skc-leto 



('/,i 



''. o". 



b, sadiUt-like disk fcriiied by tlio cutdesceucc of Uie iitiira|n.iiliysc.-s <■£ tlit tirst abd in;d vertetirii-; //A//, biisibyoid; cc, finteriipr 0]>cTtiire of tlie 



ethmoidal canal; c/i, uotoehord; chy, eeratoliyoid; cp. |ir<orliilal uanal, passage of tlie raiinis uphtliahnicus stqierior nervt trigemini to the 

 ethmoidal, eaiial; du. anterior dental plate of the upper jaw; ili. dental plate of the lower jaw; dp, posterior dental plate of the upper jaw; 

 fa, foramen for a branch of the facial nerve; fO, iibrils of the anterior dorsal and the pectoral fins; li. rudimentary ha?niapophyses; /;»», hyo- 

 maudibular; iktd, spine (ichthyodorulite) of the anterior dorsal fin; in, interneurals; //, fronto-unsal cartilage (prehensile organ of the male); 

 Imi. labial cartilage of the lower jaw; Ims, labial cartilage of the upper jaw; //(,, first labial cartilage of the nasal capsule; fe.^, second labial 

 cartilage of the nasal capsule; /;■,, first rostro-nasal cartilage; /;■,, second rostro-nasal cartilage; mb, posterior, fibril-less membrane of the first 

 dorsal fin; iii)t. mcxopterygiiim ; mI,, first part of the metapteiyc/iitiii; mt.,, second part of the metajiterygium ; N, nasal capsule; nn, neurapo- 

 physes; occ, occipital condyles; on, orbitonasal canal, passage of the ramus ophthalmicus profundus nervi trigemini to the ethmoidal canal; 

 opt, optic foramen; pp, propterygium ; ijpg, palatoquadrate; R, imdivided radial (interspinal) cartilage of tlie first dorsal fin; rb, foramen for 

 the ramus buccalis nervi trigemini; s, Solgerian (spiracular) cartilage; sc, scapular cartilage; sp. tegumentary cartilage of the spinal canal 

 {processus spinosi superioms); ssc, suprascapular cartilage; sy, symplecticuiu; tr, foramen for the trigeminal and facial nerves; trs, foramen 

 for the ramus ophthalmicus nn'vi trigemini: 1 — ff, first (proximal) to sixth (distal) scries of the pectoral radialia. 



senting an os ilii. In the ('him;vras this proems runs i originally continuous dermal folds — unpaired along the 

 80 far up, more in a straight line with the pelvic disk, dorsal and inferior caudal margins, but double (paired) 

 as to unite bv means of ligaments the pelvic girdle cm the ventral side, as having been divided to surroinid 



