TRIBE I. ASTR^ACEA. OQ5 



species that have the interstices between the cells quite flat, and the 

 lamellae minute, closely crowded, and slightly prominent; they much 

 resemble some of the aggregate species of the Fungia family, and 

 are near the Psammocorse. They may possibly be shown to have the 

 essential characters of the Fungidae, but are for the present arranged 

 here, in the subgenus Siderina. They form part of the group Sideras- 

 trrea of Blainville. 



Arrangement of the Species. 



SUBGENUS 1. ORBICELLA. Cells nearly circular, more or less prominent, not sub- 

 dividing by growth, or rarely so ; stars with distinct limits formed by the coalescence 

 laterally of the lamellae, and therefore cells appearing tubular and separated by inter- 

 stices. 



I. Calicles prominent, cells more than 2 lines broad, lamellce in adult cell, 36 or 48. 



1. A. Orb. radiata. *5. A. Orb. curta. 



*2. A. Orb. argus. 6. A. Orb. rotulosa. 



*3. A. Orb. glaucopis. *7. A. Orb. coronata. 



*4. A. Orb. patula. 



II. Calicles more or less prominent, cells less than 2 lines broad, lamettce in adult cell, 

 18 or 24. 



*8. A. Orb. hyadcs. *13. A. Orb. stelligera. 



*9. A. Orb. excelsa. 14. A. Orb. crispata. 



*10. A. Orb. pleiades. *15. A. Orb. microphthalma. 



*11. A. Orb. annularis. *16. A. Orb. ocellina. 



*12. A. Orb. stellulata. 



SUBGENUS 2. SIDERINA. Cells not subdividing by growth, interstices flat, stars with 

 limits along the middle of the interstices, and cells not appearing tubular; lamella? minute 

 and crowded. 



*17. A. Sid. galaxea. 



SUBGENUS 3. FISSICELLA. Cells subdividing by growth and budding. 



A. CONVEX OR ROUNDED. 



a. Cellules of the stars in a transverse section decompound, lamellae even. 



I. Calicles prominent. 



*18. A. speciosa. *21. A. pandanus. 



19. A. uva. *22. A. puteolina. 



20. A. ananas. *23. A. pallida. 



II. Calicles immersed, ridges someu-hat sukate or entire. 



*24. A. dipsacea. *27. A. fusco-viridis. 



*25. A. porcata. *28. A. virens. 



*26. A. flexuosa. *29. A. echinata. 



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