EXPLANATION OF PLATE XVII. 
SKULL OF RHAMPHICHTHYS ROSTRATUS (Linneus). 
Fig. 1, dorsal view; Fig. 2, lateral view. art., articulare; exo., exoccipital; fr., frontal; hy. m., hyo- 
mandibular; in. op., interoperculum; man., mandible; mesth., mesethmoid; mptg., metapterygoid; mx., maxil- 
lary; nas., nasal; op., operculum; par., parietal; p. mx., premaxillary; pr. op., preoperculum; pter., pterotic; 
plg., pterygoid; qu., quadrate; s. occ., supraoccipital; s. op., suboperculum; sph., sphenotic; su. scap., supra- 
scapular; sym., symplectic. 
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