360 MANUAL OF ELEMENTARY ZOOLOGY 



olf.o. 



Fig. 258. — The forepart of 9 dogfish, dissected from the ventral side, 

 to show the dorsal arterial system, the olfactory organs, and 

 certain structures in the orbits. The middle part of the floor of 

 the mouth has been removed. 



a.b.a., Afferent branchial arteries; c,c, t common carotid artery; coe.a., cceliac 

 artery; d.ao., dorsal aorta; e.o,a. t efferent branchial arteries; e.c, external 

 carotid; en,, nostril; epibr., epibranchial artery; hm. t hvomandibular car- 

 tilage; hy.a., hyoidean artery; r'.c, internal carotid arteries; inf, t infundi- 

 bulum ; M.c, Meckel's cartilage in lower jaw; o.i. t inferior oblique muscle; 

 o.s., superior oblique muscle; olf.o., olfactory organ; p.c. t posterior carotid 

 artery; sc, scapula; set., subclavian artery; s&., skull; sp., spiracle; V.ntd. t 

 V,mx. % mandibular and maxillary branches of fifth nerve ; //., optic nerve. 



