Plate XIX. 



Asterias pallida (Ag.). 



All the figures in this plate are magnified 60 diameters. With the exception of 

 Fig. 13, they were drawn from specimens mounted in balsam. The former was drawn 

 in alcohol ; hence the disproportion in size between it and the rest. 



Stage B. 1. A fully developed bipinnaria seen from the left side. 



„ 2. Ditto, from the left side, showing the body cavities. 



,, 3. Ditto, from the ventral side. 



,, 4. Ditto, from the right side. 



Stage C. 5. A young brachiolaria seen from the left side. 



,, 6. Ditto, from the left side, showing the body cavities. 



,, 7. Ditto, from the ventral side. 



,, 8. Ditto, from the right side. 



Stage D. 9. A fully developed brachiolaria seen from the left side. 



Stage E. 10. Brachiolaria undergoing metamorphosis into the star, from the 

 left side. 



,, 11. Ditto, from the left side, showing the body cavities. 



,, 12. Ditto, from the right side. The anterior enteroeoel has not been com- 

 pletely separated from the posterior enteroeoel on the right side. 



Stage F. 13. A still more advanced stage of metamorphosis, from the dorsal side. 



Stage G. 11. Metamorphosis nearly completed,'' from the dorsal side. 



,, 15. Ditto, from the anterior pole. 



Stage H. IG. Metamorphosis just completed, from the anterior pole. 



Posterior median 

 Posterior ventral 

 Posterior dorsal 

 Anterior dorsal 

 Anterior ventral 



tentacles are paired. 



ABBREVIATIONS. 



an. pro protoproct. 



brach, d right brachiolaria arm. 



,, med median „ „ 



s left 



can. aq pore canal. 



can. aren stone canal. 



cav. perihsem. ... peribaemal cavity, 

 ent'c'l. a anterior enteroeoel. 



,, cir circular „ 



„ epigas.... epigastric ,, 



,, p. d right posterior enteroeoel. 



„ p. s left „ 



,, p'. s' secondary left posterior en- 

 teroeoel. 



„ periœs.... periœsophageal enteroeoel. 



gast stomach. 



int intestine. 



sin. ax axial sinus. 



sin', ax' closed portion of the axial 



sinus. 



tent. dor. a anterior dorsal tentacle (= 



Ijipinnaria arm.) 



„ „ p posterior dorsal tentacle. 



,, med. a anterior median „ 



„ ,, p- ..... posterior „ „ 



,, veu. a anterior ventral ,, 



,, „ p posterior „ „ 



vas. aq. cir. ...... circular water-vascular canal. 



,, ,, rad radial ,, ,, ,, 



