THE MARSIPOBRANCHII. 147 
figure indicates the superficial resemblances 
between the labial cartilages of the two genera 
‘ abovenamed. Nat. size. 
Fig. 7. Median longitudinal section of the head of Ces- 
tracion (? sp.). The coarsely stippled areas repre- 
sent those of development of diffuse buccal scutes. 
| Reference Letters. 
The terms employed in dealing with the cartilages are 
a modification of those of Huxley (Jour. Anat. and Phys. 
Vol. X, pp. 412—428); the chief alterations being the 
addition of ventro-external, and the substitution of antero- 
ventral, lateral, postero-ventral, and ventro-internal, for 
his ‘‘ median ventral,’ ‘‘ postero-lateral,’’ ‘‘ lingual,” and 
‘“‘ antero-lateral.”’ 
a.d. antero-dorsal cartilage; aw. auditory capsule; an. 
annular cartilage; a.v. antero-ventral cartilage; b.s’. basi 
hyoid cartilage; b.s''. basi branchial cartilage; c.c. cep- 
halic clasper; ch. notochord; cl’. spiracular gill cleft ; 
el’, first branchial cleft; cl’’’. second branchial cleft; 
en. cornual cartilage; co. cesophageal coecum; cr. cranium ; 
cr’. cranial roof; cr’’. basis craniu; J. lateral (Meckel’s) 
cartilage; /b 1 to ix. labial cartilages; m. mouth; me. 
Meckel’s cartilage; m.l’. superficial lingual muscles; m.1’’. 
deep lingual muscles; my. myelon; @. cesophagus; p.d. 
posterior-dorsal cartilage; p.g. subocular arch (palato- 
quadrate cartilage); p.v. postero-ventral cartilage; qu. 
quadrate lobe of sub-ocular arch; st. styliform process ; 
v.e. ventro-external cartilage; v.2. ventro-internal cartilage. 
