Plate XV. 



Fig. 1. Sectiun of a portion of the skin of the lower side of head of the Common 

 Sole ; magnified 70 times. Reference letters as in Fig. 7, PI. XIV, with 

 the addition of /"/, tactile filaments. 



Fig. 2. Lower side of the head of the Sole dissected to sliow the cutaneous nerves : 

 natural size, 



V 2. Maxillary branch of the 5th. 

 V 2 a. palato-nasal branch of 5th. 



V 2. mandibular branch of 5th. 

 VII 1. mandibular branch of 7th. 

 VII 2. hyoidean branch of 7th. 



VII 2 a. opercular branch of 7th. 

 X 6 a. supra-temporal branch of vagus. 

 X 6 Z*. another anterior branch of the vagus. 



Fig, 3. Egg of Cominon Sole taken in tow-net in Mount's Bay, March 1, 1SS9. 

 Magnified 45 times, hi. blastoderm, y.s. yolk segments, o.(j. oil globules. 



Fig. 4. An egg of the same, artificially fertilised, March 23, 7 a.m. ; drawn March 24, 

 5 p.m.; same magnification. 



Fig. 5. An egg of the same, artificially fertilised, March 23, 7 a.m. ; drawn March 25, 

 12 noon ; same magnification. 



Fig. ti. An egg, fertilised artificially. April 12, 188'J ; dranw April 15, 4 p.m. 

 Both black and coloured pigment cells present, the latter green by reflected 

 light; e. eye, m.s. mesoblastic somites. 



