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EDWARD PHELPS ALLIS. 
EXPLANATION OF PLATE 6 , 
Illustrating Mr. Edward Phelps Allis’s paper on “ The 
So-called Labial Cartilages of Raia clavata.” 
Index Letters. 
a. n. Ala nasalis. a. n. a. Anterior nasal aperture, ant. Antorbital 
cartilage (Parker), Schadelflossen-Knorpel (Gegenbaur). f.n. Fenestra 
nasalis. m. mouth, md. Mandibula. n. Nasal section of latero- 
sensory canal, n. b. g. Naso-buccal groove, n. c. Nasal capsule. n.f. 
Nasal flap, n.f.c. Nasal-flap cartilage, n.f.f. Nasal-flap furrow. 
orb. Orbital section of latero-sensory canal, pn. Pre-nasal section of 
latero- sensory canal, p. n. a. Posterior nasal aperture, pq. Palato- 
quadrate. r. b. Ramus buccalis lateralis, r. mx. t. Ramus maxillaris 
trigemini, so. Suborbital section of latero-sensory canal, sr. Subrostral 
section of latero-sensory canal, u. 1. c. Upper labial cartilage. 
Fig. 1. — Ventral view of the snout of Raia clavata. On the- 
right-hand side of the figure the dermis has been removed from the 
nasal flap so as to expose the ala nasalis, the nasal-flap cartilage, and 
the related sections of the nasal and pre-nasal latero-sensory canals. 
Fig. 2. — The same ; a deeper dissection. The nasal flap has been 
almost completely removed on both sides of the figure. On the left- 
hand side that part of the flap that contains the anterior process of 
the ala nasalis has been left and turned back so as to expose the nasal 
apertures and the nasal-flap furrow. 
Fig. 3. — The same; a still deeper dissection. The nasal flap and 
the related portions of the latero-sensory canals have been removed 
on the right-hand side of the figure, exposing the ala nasalis and the 
upper labial cartilage. On the left-hand side these last two cartilages 
have been removed so as to expose the nasal capsule. 
