MUSEUM OF COMPARATIVE ZOOLOGY. 77 



EXPLANATION OF PLATES. 



PLATE I. 



Figure 1. Eudendrium, sp. Remnant of a colony springing from a thickened fas- 

 cicled liydrorliiza. Natural size. 

 " 2. Eudendrium, sp. The same species. Natural size. 

 " 3. Obdla castellata, sp. nov. The entire specimen enlarged 10 times. 

 " 4. 0. castellata. A portion of the trophosome. X 52. 

 " 5. 0. castellata. A single liydrotheca in which occurred an uneven line in 

 the exact position for a floor or hottom. The hydrotheca is badly 

 wrinkled. X 52. 

 " 6. 0. castellata. The entire specimen. Natural size. 

 " 7. 0. castellata. A gonangium with its position on tlie stem. X 52. 

 " 8. 0. castellata. Another gonangium in which there is a long wrinkle. 



X 52. 



PLATE II. 



Figure 9. 0. castellata. A gonangium. X 52. 



" 10. 0. gelatinosa. A gonangium introduced for comparison. X 52. 



" 11. 0. (jelatinosa. A hydrotheca, for comparison with those of 0. castellata. 



X 52. 

 " 12. Halecium argenteum, sp. nov. Portion of a branch. X 52. 

 " 13. //. ((ir/enteum. Natural size. 



PLATE in. 



Figure 14. LictoreJla geniculata, sp. nov. Part of a stem and branch. X 40. 

 15. L. geniculata. X 88. 

 " 16. L. geniculata. An entire colony. Natural size. 



PLATE IV. 



Figure 17. Sertularia variabilis, sit. nov. A colony with a compound stem. Natural 



size. 

 " 18. S. variabilis. A colony witli a simple stem. Natural size. 

 " 19. S. variabilis.' A single hydrotheca. v, the valves; o, tlie opening by 



which it communicates with the cavity of the stem; g, the aperture 



where the gonangium was attached. X 52. 

 " 20. S. variabilis. A portion of the trophosome with one gonangium. X 20. 



PLATE V. 



Figures 21 and 22. Sertularia rariidulis. X 20. 



