76 PEOF. p. MAETIIf DTJKCATSr's REYISIOIS' OF THE 



tlie second of tlie sections mentioned above, run into tlie Euphyl- 

 liacees confluentes ; and this want of definition is observable in 

 the Astrseinse caespitosse and confluentes. 



It does not seem possible to separate sucb genera as Musmilia, 

 Aplosmilia, and EupJiyllia from Dasyphyllia, TracJiyphyUia, and 

 Mussa, and their subfamily relationship is evident. The genus 

 Plocophyllia, Eeuss, is an Eusmiline Mussa in habit of growth. 



In both of the sections the corallites spring from a small base 

 or parent, either by budding or by fissiparity. They then increase 

 by fissiparous division. The divided parts grow upwards, become 

 separate, and do not unite at the sides. Sometimes this fissiparous 

 division does not take place until the calicehas become very long, 

 and even gyrose, so that a kind of serial growth occurs before 

 separation, and it may persist in some parts of the colony, or tini- 

 versally. One part of a fissiparous calice may grow faster than 

 the other, and the calicular centres of the new corallites become 

 evident sooner or later in all conditions, except in the long serial 

 gyroid calices seen in JEtipliyllia for instance. 



Seventeen genera have been noticed, but thirteen only remain 

 after revision. Two become subgenera. 



Alliances. 



I. Calamophyllioida. 

 II. Thecosmilioida. 



III. MUSSAOIDA. 



I. Alliance CALAMOPHYLLIOIDA. 



Csespitose Astrseidse in colonies, the corallites of which speedily become 

 separate, except at their lower and originally attached part. Calices more 

 or less circular, very rarely forming short series. 



Tribe I. "With entire septa. 

 „ II. With dentated and spined septa. 



Tribe I. 



Genus Eusmilia, Ed. & H. 



Subgenus Caulastr^ea, Dana. 

 Genus Aplosmilia, d'Orbigny. 

 Genus Solenosmilia, Duncan. 



Tribe II. 



Genus Dasyphyllia, Ed. & H. 

 Genus Calamophyllia, Ed. & H. 



