1070 
SCANDINAVIAN FISHES. 
Fig. 298. Skull of Rough Hound ( Scylliorhinus Canicula ), seen from above (A), from the right ( B ), and from behind (6 T ). Natural size 
After Parker. 
aqv, aquceductus vestibuli; asc, external prominence of the anterior semicircular canal of the labyrinth; bbr, basibranchiale (copula) ; br, car- 
tilaginous rods of the branchial membranes; cbr , 5 , ceratobranchials of the first — fifth branchial arches; ch, space for the notochord, filled 
with cartilage; chy, ceratohyoideum; cp , preorbital canal; ctr, cornua trabecidarum in the floor of the skull, seen through the prefrontal 
fontanelle; ebr x ., epibranchials of the first — fifth branchial arches; evs, extravisceral cartilages; fom, foramen magnum; fspo , supraorbital 
foramen; gp, foramen for the nervus glossopharyngeus ; libr x 2 , hypobranchials of the first and second branchial arches (other hypobranchials 
not denoted); km , hyomandibulare ; hsc, external prominence of the horizontal (outer) semicircular canal of the labyrinth; la, anterior suspen- 
sory ligament, for the palatoquadrate cartilage; hni, labial cartilage of the lower jaw; Ims , labial cartilage of the upper jaw; /«, anterior 
and outer nasal labials; Ip, posterior suspensory ligament, for the palatoquadrate cartilage (upper jaw) and the mandibular arch (Meckelian 
cartilage); Ir, rostral labials; Mb, Meckelian cartilage (lower jaw); N, nasal capsule; occ, occipital condyles; opt, optic foramen; phbr x 5 , 
pharyngobranchials of the first — fifth branchial arches; prob , preorbital process; psc, external prominence of the posterior semicircular canal 
of the labyrinth; ptoli, postorbital process; ptp, suspensory process of the pterygopalatine arch; qpq, pterygopalatine cartilage; R, rostral 
cartilage; r. br, brancliiostegal rays; spc, spiracular cartilage; spir, spiracle; tr, foramen for the nervus trigeminus ; vag, foramen for the 
nervus vagus. 
