474 



HENRY C. TRACY 



LSCA, ampulla of lateral semicircular 

 canal 



LW, lateral wing of prootic 



LWF, lateral wing of frontal 



M, muscle 



MPRO, mesial plate of prootic 



NC, nasal cartilage 



OBSP, orbitosphenoid 



ON 1, first occipital nerve 



ON 2, second occipital nerve 



OFF, optic foramen 



OPS, ramus ophthalmicus superficialis 



OPT, opisthotic bone 



PF, parietal bone 



PMV , posterior membranous vesicle 



FN , branch of VII nerve to ampulla of 

 posterior semicircular canal 



POC, posterior osseous capsule 



PRO, prootic bone 



PS, perilabyrinthine tissue space 



PSC, supracerebral perilabyrinthine 

 canal 



PSD, posterior semicircular canal 



PSD A, ampulla of posterior semicir- 

 cular canal 



PSP, parasphenoid bone 



PSPW, posterior wings of parasphe- 

 noid 



FT, pterotic bone 



R VII, recurrent ramus of VII nerve 



RE, rectus eye muscles 



RHM, ramus hyomandibularis 



RMM, ramus maxillomandibularis 



RP VII, ramus palatinus of VII nerve 



RPT , ramus pretrematicus 



RSY , ramus sympatheticus 



S, sacculus 



SB, swimbladder 



SEP, synchondrosis between basioc- 

 cipital and prootic 



SC, septum of anterior osseous capsule 



SCA , prootic portion of saccular cavity 



SCF, subcerebral plate of perilabyrin- 

 thine tissue 



SLF, superior lamina of falciform pro- 

 cess of prootic 



SN , saccular division of VIII nerve 



SOC, supraoccipital bone 



SOL, supraorbital lateral line canal 



SPH, sphenotic bone 



SR, saccular recess 



SS, superior sinus of utriculus 



SSC, saccular subcerebral canal 



TF, temporal foramen 



TPEXO, triangular plate of exoccipital 



VM, vomer 



VT, vertebra 



VBSO, ventral plate of basioccipital 



VPRO, ventral plate of prootic 



U , utriculus 



use, utricular subcerebral canal 



III, oculomotor nerve 



IV , trochlear nerve 



V , trigeminal nerve 



VI, abducens nerve 

 VIII, acoustic nerve 



7A', glossopharyneal nerve 



A', vagus nerve 



*, foramen for ramus palatinus VII 



X, foramen for hyomandibular nerve 



PLATE 1 



EXPLANATION OF FIGURES 



1 Lateral view of skull of Pomolobus pseudoharengus. X 4.5. 



2 Ventrolateral view of posterior part of skull of Alosa sapidissima. X 2. 



