Fig. 10. Goniocidaris canaliculata Al. Ac. Same specimen as Pl. II, fig. 

 '5, opened so as to show tlie intestine, seen from abovc, n tlie anterior, 

 p the posterior termination of the intestine; * the rectum, the aqui- 

 ferous canal. the ovoid glaiul and the lilood lacnnes in conncxiou. 



Fig. 11. The same, side view. 



Fig. 12. The same, ventral view of the intestine. Tlie six lines refor to the 



Fig. 13 — 18. Six vertical sections through tlie intestine, and fig. If) through 

 the oesophagus, fig. 17 through the reetum. 



Fig. 19. Another specimen, decalcified, seen from above. Ilorizontal seetion 

 showing the test with spines, pedicels, ambulacral vessels and the 

 intestine. The plaue of the seetion is somcwhat slanting. from III, 

 where it cuts the uppermost ambnlaorals, to a))out I, falling in there 

 with the third pore from the radial. a is tlie anterior termina- 

 tion of the intestine, oes. the oesophagus; p its posterior termina- 

 tion, near the anterior end the aquiferous canal. the ovoid gland, 

 and the blood lacunes are seen cut through. 



Fig. 20. Another horizontal seetion. Both ends of tlie intestine; ocs. the 

 oesophagus. 



Fig. 21. The innermost laj^er of the costal 2 with the water-pore; r. the ree- 

 tum, int. the intestine; cal. part of the ealyx. 



Fig. 22. The same sjjeeimen as fig. 10. Inside view of peristomals I. ;"> and 

 V, showing the two half-pyramids of o with the tooth and tlie mus- 

 cles, m. re. and m. pro. attached to the solitary peristomal T), tlie 

 beginnings of the epiphyses, cp.. and of the rotulff, ro. 



Fig. 23. Side view of the dental api)aratus of another specimen with the rai- 

 sed half-pyramids beginning to enclose the tooth. 



Fig. 24. Horizontal seetion, tinctured with borax earmine, of the two half- 

 pyramids and the tooth. d.; me. tlie enveloping memliranc. 



