ON THE GENERAL MORPHOLOGY OF THE MYXINOID FISHES. 787 
f.r. The so-called “ fin rays” composed of soft pen Parachordal” cartilage. 
cartilage (although not coloured). p. d. p. Posterior arch of the dental plate. 
h. p. Hypophysial plate. pl. | REECE bar. 
h. p.. Rod connecting above with the posterior p. q. “ Pterygo-quadrate. 
transverse bar of the nasal capsule (figs. p. t. b. Posterior transverse bar of the nasal cap- 
1 and 2). sule. 
hy. “Hyoid” arch. p.t.v. b, Posterior transverse velar bar. 
7. b. p.’ Internal bar of the anterior segment of 8. g. 8. Secondary ground substance of the hard 
the basal plate. cartilage. ; 
7. l. 6. Internal lateral velar bar. sk. 1, Skeletogenous layer of the notochorda 
i. 1. c. Inferior lateral cartilage. sheath containing elastic fibrils exter- 
7. r. t. Inner row of ventral teeth. nally. 
1.1. Tendon of the M. longitudinalis lingue s. 1. c. Superior lateral cartilage. 
(P. FUrBRInGeR) cut across (= the sn. b. Subnasal bar. 
tendon of the M, retractor mandibuli, sp. c. Membranous neural tube. 
Ayers and Jackson). sp. cd. Spinal cord. Note the expanded termina- 
1. 1. c. Lateral labial cartilage. tion. 
1. p. Lateral plate of the nasal capsule. sp. He Suprapharyngeal skeleton (fig. 1). 
m. d.b. Median dorsal bar of the caudal fin sp. sles Anterior | connecting processes of the 
skeleton. sp. sk.” Median j 
m., v. b, Median ventral bar of the caudal fin suprapharyngeal skeleton. In Bdello- 
skeleton. stoma, according to AYERS and JACKSON, 
n. c. Nasal capsule. all three fuse with a median dorsal 
n. ct. c. Nucleus of the cartilage cell. suprapharyngeal plate represented in 
nt. Notochord. Mywine by the expanded extremity of 
nt. sh.—* External, middle, and internal layers of ; sp. sk. A 
the fibrous notochordal sheath. | ir. “ Trabecula. 
1—4 7 
ances! tube. hes The various portions of the branchial 
ad es oh. skeleton. Cp. text. 
o. r. t. Outer row of ventral teeth. ge 
Puate I, 
Fig. 1. Dissection from the left side of the skull of a 454 cm. Hag. x4. Tentacular cartilages and the 
rings of the nasal tube numbered from before backwards. ‘Lhe colours and shading indicate the different 
kinds of cartilage, and also the staining reactions of the same with Mann’s methyl-blue-eosin: hard cartilage, 
red ; soft cartilage, blue ; hard pseudo-cartilage, blue (dotted) ; soft pseudo-cartilage, uncoloured and obliquely 
striated. 
Fig. 2. Dissection from the dorsal surface of the skull of a 454 cm. Hag. x4. Tentacular cartilages 
numbered from before backwards. The third tentacle, branchial arches, and suprapharyngeal + velar 
skeleton have been displayed for the sake of clearness. Nasal tube and capsule removed, and dental 
skeleton not shown. The correct relations of the parts have been maintained (cp. in this respect AYERS’ and 
JacKson’s fig. 7). Colours, etc. as in fig. 1. 
Puate II. 
Fig. 3. Transverse hand section of the “hard (brown) cartilage” taken from the middle segment of the 
basal plate of a 35 cm. Hag, and stained with Mawnn’s methyl-blue-eosin. Zeiss apochr. 1°5 mm., compens. 
oc. 4. 
Fig. 4. Portion of transverse hand section through the posterior segment of the basal plate of the same 
fish, to illustrate the structure of the “hard pseudo-cartilage.” Methyl-blue-eosin. The upper border is the 
dorsal concave and the lower the ventral convex border of the cartilage. Same lens and eye-piece as fig. 3, 
but much less magnification. 
