iMtJSTKLUS L^.vis. 235 



DESCRIPTION OF PLATES 10—12, 



Illustratmg tlie paper by Mr. Edward Phelps Allis, jun., 

 on "■ The Lateral Sensory Canals, the Eye Mnscles, and 

 the Peripheral Distribution of the Cranial Nerves of 

 Mustelus 1 83 vis." 



Fig. 1. — Side view of t.lie head of a 10 cm. embrjo of Mustelus Isevis, 

 the skiu beinj^ removed so as to expose the lateral and ampuUary cauals. The 

 surface pores of the lateral canals are not shown at all ; and very few of the 

 tubules of the canals, excepting those that project to one side or the other, 

 are even indicated. X 9. 



Fig. 2. — Top view of the same, x 9. 



Fig. 3. — Bottom view of the same, x 9. 



Fig. 4. — Side view of a deeper dissection of ihe same head. The lateral 

 and ampullary canals, the eyeball, and the eye muscles have been removed, 

 the other muscles being all left in place. Part of the ampullae have been 

 removed, others being left in place. X 9. 



Fig. 5. — Bottom view of the same. X 9. 



Fig. 6. — Side view of the skull of a 10 cm. embryo of Mustelus laevis. 

 X 5. 



Fig. 7. — The suborbital section of the infra-orbital canal of a 10 cm. 

 Mustelus 1 86 vis, showing the tubules and pores of the canal, x 12. 



Fig. 8. — Part of a transverse section of a 122 cm. embryo of Mustelus 

 Iffivis, showing the adductor mandibular and Ad(l/3 muscles, the mandibular 

 cartilage, and the anterior upper labial cartilage. 



Fig. 9. — Part of a more posterior section of the same embryo, showing also 

 the anterior end of the jiosterior upper labial cartilage, with a part of the 

 tendon of the muscle Add/3 inserted on it. 



Index Letters. 



cicafr. Foramen of anterior carotid artery, acrfr. Foramen of anterior cere- 

 bral vein. Addji. Muscle Add/3 of Vetter's descriptions. Am. Adductor 

 mandibulse. ba. Buccal group of ampullae or their pores and tubes, ba.'^'' 

 Five sub-groups of buccal ampullary pores and tubes, b/. Ramus buccalis 

 facialis. ^.?//a'. ot6?. Truncus buccalis-maxillo-mandibularis. d. Canalis trans- 

 versus. Csd.^. Muscle Csdo of Vetter's descriptions. CsVc,. Muscle (Jsv; of 



