1910.] 



anatomy of the frilled shark. 

 Reference Letters. 



571 



Skull. 



a.f., anterior fontanelle* 

 bbr. 1-6, basibrancbials* 



bh., basihyal. 

 br.r., branchial rays. 

 cbr., ceratobranchials, 



ch., notochord. 

 crh., ceratohyal. 

 ebr., epibranchial. 

 e.p.p., ethmo-palatine process. 

 f., foramen. 

 hbr. 1-6, hypobranchials. 

 hym., hyomandibular. 

 hy.p., hyal process. 

 i.c.f., internal carotid foramen* 

 i.o.s,, interorbital sinus* 

 J. I., joint ligament. 

 l.h.m.e., ligamentum hyoideo mandibu- 

 lar externum. 

 l.q.h.i., ligamentum quadrato - hyoideo 

 internum. 



m., mandible. 

 m.r. , mandibular ridge. 

 n.c, nasal cartilages. 

 o.c, olfactory capsule. 

 o.s., optic stalk. 

 pf., parietal fossa. 

 po.p., postorbital process. 



jpq., palaloquadrate. 

 pr.p., preorbital process. 

 p.s.l., post-spiracular ligament, 

 pt.f., pituitary fossa. 



v., rostrum. 

 s.Cir., supra-capsular ridge. 



s.o. 1-4, spino-occipital foramina. 

 sp,r t , supraorbital ridge. 

 th.c, thyroid concavity. 

 v.b.a.7., vestigial 7tb branchial arch, 



I-X., cranial nerve foramina. 

 Yil.h.j hyoidean foramen of VII. 



Membranous Labyrinth. 



s.e. f 



t; 



u.a., 

 u.p., 



a.a., ampulla anterior. 



a.d.e., apertura ductus endolymphati 

 cus externus. 



a.e., ampulla externus. 



a. p., ampulla posterior, 



c.a., canalis anterior. 



c.6., canalis externus. 



c.p., canalis posterior. 



(I.e., ductus endolymphaticus, 



d.u.s.p., ductus utriculo saccularis 

 posterior. 



I., lagena. 



p.f., parietal fossa. 



r.a.a., ramulus ampulla alitei'ior. 



Vertebral Column 



a.ch.s., ambulation of chordal sheath. 

 bd., basidorsals. 

 bv., basiventrals. 

 cal., calcifications. 

 c.c, cyclospondylie centra. 

 ch.s., chordal sheath. 

 d.f., dorsal root foramina. 

 h.c, haemal canal. 

 h.s.. hcemal spines. 

 id., interdorsals. 

 i.bd., imperforate basidorsals. 

 i.id., imperforate interdorsals. 



r.a.e., ramulus ampulla externus. 

 r.a.p., ramulus ampulla posterior. 

 rec, recessus utriculi. 

 r.l., ramulus lagena. 

 r.n., ramulus neglectus. 

 r.s., ramulus sacculus. 

 r.u., ramulus utriculi. 

 s., sacculus. 



saccus endolymphaticus. 

 tympanic aperture, 

 utriculus anterior, 

 utriculus posterior. 



VIII., 8th cranial nerve. 



iv., interventrals. 

 iv.s., intervertebral spaces. 

 l.c.c, larger cyclospondylie centra. 



»., neuromeres. 

 ne.c, neural canal. 

 p.bd., perforai-e basidorsals. 

 p.id.. perforate interdorsals. 



rb., ribs. 

 s.bd,, supra basidorsals. 

 s.c.c, smaller cyclospondylie centra. 

 sd.l., supra-dorsal ligament. 



of., ventral root foramina. 



A, muse, adductor. 



B, basipterygium. 



b., axial cartilage. 

 6.1, intercalary cartilage. 

 j3, modified radial. 

 bt.d., distal segment of basiptery- 

 gium. 

 bt.p., proximal segment of basi- 

 pterygium. 

 c.n., collector nerve. 

 D, muse, dilatator. 

 Fl.e., muse, flexor externus. 

 FLi., muse, flexor interims. 

 i.n.f., longitudinal nerve foramina. 



Paired Fins. 



1.7 



last lateral radial. 

 mst., mesopterygium. 

 mt., metapterygium. 



O, dorsal radial muscles. 

 p.g., pelvic girdle. 

 pt., propterygium. 

 pt.r., postaxial radials. 

 r., lateral radials. 

 Ra., ventral radial muscles. 

 JR,i\, marginal ventral cartilage. 



S, muse, compressor. 

 T.d., terminal dorsal cartilage. 

 T.v., terminal ventral cartilage. 



