940 



PROFESSOR W. C. M'INTOSH AND MR E. E. PRINCE ON 



Fig. 16. G. aiglefinus, transverse section showing a tract, probably sensory, in the lateral region of 

 the tail, ........ 



Fig- 17. ,, transverse section near the tip of the caudal trunk, 



Fig. IS. T. gurnardus, 22 days old, bony elements in the roof of the mouth, probably palatines, 



Fig. 19. Clavicle of undetermined pleuronectid larva (possibly plaice), 



Fig. 20. T. gurnardus, 22 days old, premaxillary (?) elements : a, anterior extremity ; b, posterior. 



Plate XII. 

 T. gurnardus, 1st day out, June 2, 1886, . 

 G. morrhua, advanced larva, May 2, 1855, 

 Early larva of Motdla mustela, May 8, 1886, 

 Molva vulgaris, just hatched, 4.30 p.m., May 5, 1886, 

 Cydopterus lumpus, newly-hatched, May 27, 1886, 

 Larva of Pleuronedes flesus, 13 days old, April 26, 1886, 



,, „ ,,13 days old, dorsal view. 



Lateral view of the larva of P. platessa, May 7, 1886, . 



G. aiglefinus, 6 days old, longitudinal vertical section through pericardial chamber, sinus 

 venosus, and branchial arches, ....... 



Fig. 



1. 



Fig. 



2. 



Fig. 



o 

 O. 



Fig. 



4. 



Fig. 



5. 



Fig. 



6. 



Fig. 



6a 



Fig. 



7. 



Fig. 



8. 



x230 



x230 



xl20 



x 70 



xl20 



x about 32 



x 45 



x 60 



x 40 



. Magnified 



x 50 



40 



150 



Plate XIII. 



Fgi. 1. Larva of Liparis montagui, March 19, 1886, 



Fig. 2. Termination of the tail in the larva of Coitus scorpius, April 8, 1886, 



Fig. 3. Ovum of undetermined pleuronectid (?), with large perivitelline space. 



Fig. 4. Molva vulgaris, 1st day out, May 6, 1886, 



Fig. 5. Centronotus gunnellus, head and anterior region, March 18, 1886, . 



Fig. 6. „ ,, early larva, March 14, 1886, 



Fig. 6a. Caudal region of larval gunnel, ..... 



Fig. 7. Centronotus gunnellus, advanced larva, May 1, 1886, 



Plate XIV. 



Fig. 1. Embryo of G. ceglefinus, removed from capsule, April 1, 1886, viewed somewhat obliquely, 



Fig. 2. Head of larva of T. gurnardus, 3rd day, 



Fig. 3. Abnormal tail of larva of T. gurnardus, 1st day, June 7, 1886, 



Fig. 4. Anterior end of larva of Cottus scorpius (V), April 8, 1886, 



Fig. 5. P. platessa, anal region, ..... 



Fig. 6. Cardiac region of larva from ovum with large perivitelline space, 



Fig. 7. T. gurnardus, hind end of embryo and edge of blastopore, showing the adjoining nuclei of 



the periblast, ....... 



Fig. 8. ,, blastoderm shortly after the 6th hour, the 4th furrow in progress, . 



Plate XV. 



Molva vulgaris, subnotochordal trunks and blood-elements blc, May 8, 1886, 

 Larva of Liparis montagui (?), showing vitelline circulation, April 12, 1886, 

 Aboral end of the notochord and tail of post-larval P. flesus, 



Tip of the tail in the larval Motdla mustela, ..... 



5. Marginal fin and part of alimentary canal in the larva of Gastrosteus spinadtia, July 1 

 1885 [the caudal fin in this figure has been marked ef instead of c/], 

 Cydopterus lumpus, lateral view, 26 days old, June 17, 1885, 



Longitudinal section through the caudal portion of the notochord of G. aiglefinus, 13th day 

 P. flesus, head of young specimen, May 18, 1886, ..... 

 Cydopterus lumpus, same age as in fig. 6, ventral view showing sucker-like ventral fins, 



Fig. 



1. 



Fig 



2. 



Fig. 



3. 



Fig. 



4. 



Fig. 



5. 



Fig. 



6 



Pig. 



7 



Fig. 



8 



Fig. 



9 



x 24 



x 40 



x 40 



. x about 90 



. Magnified 



. x about 24 



. x about 24 



r, x 55 



x 55 



x210 



x 24 



x 55 



x 40 

 .t 



>i 



x210 



x 80 



x220 



x 40 



x 55 



x220 



x200 



x 30 



j, x 200 



. Magnified 



x 25 



