STEUCTUEE OF THE LARVAL POLTPTERUS. 



345 



Lettering op the Figures. 



ad. Adipose tissue. 



i.s. Intermuscular septum. 



al. Alimentary canal. 



k. Kidney. 



An.f. Anal fin. 



k.t. Kidney-tubule. 



Ao. Dorsal aorta. 



k.t.a. Accessory kidney-tubule. 



Ao.s. Aortic supports. 



Lb. Labial cartilage. 



a.p. Abdominal pore. 



l.bl. Left swim-bladder. 



Au. Auditory capsule. 



l.pr. Lateral jjrocess. 



Bas. Basipterygium. 



l.r. Lateral rib. 



b.c. Body-cavity. 



l.sp. Literspinous cartilages. 



B.Br. Basibrancbial cartilage. 



l.v.jyr. Left ventral process. 



Br. \, 2, 3, 4. Brancbial cartilages 1, 2, 3, 4. 



m.cps. Glomerulus. 



Br.n. Brachial nerve. 



m.cps.a. Accessory glomerulus. 



b.v.f. Blood-vessel foramen. 



m.c. Cartilage-like cells of membrana 



c. Centrum. 



elastica externa. 



Ch. Notochord. 



m.el.e. Membrana elastica externa. 



Ch.ep. Chorda epithelium. 



Mes. Mesopterygium. 



Ch.sh. Sheath of notochord. 



Meta. Metapterygium. 



C.Hy. Ceratoliyal. 



Mk. Mandibular cartilage. 



conv.pn.d. Convoluted pronephric duct. 



m.v. Median vesicle of brain. 



Cor. Coracoid. 



n.a. Neural arch. 



Cor.f. Coracoidal foramen. 



neph. Nephrostome. 



d.Ao. Dorsal aorta. 



n.pr. Neural process. 



d.l.ni. Doi'so-lateral muscles. 



n.sp. Neural spine. 



d.sp. Dorsal spines. 



o.l.r.c. Outer cartilages of the lateral ribs. 



eg.af. Afferent artery to external gill. 



Op. Operculum. 



eg.ef. Efferent artery to external gill. 



ov. Ovary. 



Ep. Epiphysis. 



ov.d. Oviduct. 



Ep.br. Bridge of cartilage in region of 



Pa. Palium. 



epiphysis. 



p.c.v. Posterior cardinal vein. 



Ex.xc. Exoccipital cartilage. 



P.f. Peritoneal funnel (traces of). 



f.n.pr. Fused neural processes. 



pn.c. Pronephric chamber. 



f.ol. Foramen for olfactory branches of 



pn.d. Pronephric duct. 



vth and viith nerves. 



Pr. Rudimentary continuation of 



f.v.pr. Fused ventral processes. 



radials. 



G.x. Vagus ganglion. 



Pro. Propterygium. 



g.d. Genital duct. 



P.Qu. Palato-quadrate cartilage. 



Gl. Glomus. 



P.Qu.art. Palato-quadrate articulation. 



g.r. Genital ridge. 



Pt.r. Pterotic ridge. 



gr.s.o.c. Groove for the supraorbital canal. 



r. Cartilaginous bases of radials. 



h.c. Hseraal cartilage. 



r.bl. Right swim-bladder. 



H.Hy. Hypohyal. 



rect. Rectum. 



Hy.M. Hyomandibular. 



r.v.pr. Right ventral process. 



