TRIBE I. ASTRJEACEA. 157 



The genera of Aslrseidse may be arranged and characterized from 

 the coralla as follows : 



I. Lamcllce of /lie cells large, and entire or nearly so; coralla caliciilarly branched, or 

 stipitate (cxplanato-glomerate). 



GENUS I. EUPIIYLLIA. Coralla calicularly branched, calicles subturbinate, lamellae 

 thin, bottom of the cell' very narrow and often concealed by the large lamellae. 



GENUS II. CTENOPHYLHA. Coralla explanato-glomerate, meandrine ; lamellae vory 

 stout and remote. 



II. Lamella of the cells dentate or denticulate, rarely entire and then minute ; coralla 

 calicularly branched or glomerate, the septa rarely foliaccous. 



GENUS III. MUSSA. Calicularly branched or explanato-glomerate ; calicles subturbi- 

 nate, cells large and concave, sometimes meandrine ; lamellae coarse and dentate, very- 

 unequal and unequally exsert (6 or 7 in a breadth of a fourth of an inch, and half of 

 these smaller). 



GENUS IV. MANICINA. Calicularly branched or explanato-glomerate; cells large, 

 meandrine ; lamellae very even and numerous, and neatly denticulate, rounded above. 



GENUS V. CAULASTH.EA. Calicularly branched ; cells small (hardly exceeding half 

 an inch), concave, lamellae unequally exsert, nearly entire; branches nearly cylindrical, 

 calicles not turbinate. 



GENUS VI. THIDACOPHYLLIA. Cells large, septa thin foliaceous, prominent, cristate. 



GENUS VII. ASTR^EA. Glomerate ; cell nearly or quite circular, rarely lobed. 



GENUS VIII. MEANDRINA. Glomerate, not stipitate ; cell a narrow meandering trench 

 (trench not exceeding a fourth of an inch in breadth). 



GENUS IX. MONTICULARIA. Glomerate; no distinct cells ; surface of coralla covered 

 with small lamello-radiate cones; internal texture very cellular. 



III. Coralla explanate or foliaceous. 



GENUS X. PHYLLASTR.EA. Erect, calicles large and distinct, affixed laterally to the 

 foliaceous corallum. 



GENUS XI. MERULINA. Spreading-foliaceous or ramose ; surface covered with ob- 

 lique lamellar ridges or lamello-radiate prominences, with shallow trenches or celts 

 Ix-twccn ; internal texture very compact. 



GENUS XII. ECHINOPORA. Foliaceous or ramose; surface finely echinulato-striate, 

 calicles small, nearly hemispherical and cchinulate. 



GENUS I. EUPHYLLIA.* DANA. 



Astrceidce simplicissimce, ant segregato-gemmata, raro liberce ; zoophylis 

 hemisphe.rids. Tentacula oblonga, subcequalia. Coralla calicttlato- 

 ramosa, caliculis subturbinatis, aut rotundatis aut valde compress's, 

 interdum meandrinis ; lamellisfere integris ; cettd fundo angustissimd. 



* From EU, ueU or handsome, and (puXXov, leaf, alluding to the neat entire lamellae of 

 the cells. 



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