TRIBE III. MADREPORACEA. 543 



made. Blainville reduced it to its present limits, and placed the group 

 near the Madrepores, but applied to it the name Palmipora, in allusion 

 to the palmate form of many species. Blainville's group Milleporidae, 

 embraced species of widely different characters. 



There is much difficulty in characterizing the Millepores, on account 

 of the variations of form a species undergoes, and the absence of any 

 good distinctions in the cells. The branched species are often lamel- 

 late at base, owing to-the coalescence of branches, and the lamellate 

 species, as well as the branched, sometimes occur as simple incrus- 

 tations. Weathered specimens often have the surface very crowdedly 

 pitted with minute cells, which appeared distant before weathering, 

 as but few of them reached the surface. 



Arrangement of the Species. 



I. Ramose ; or lamellate with a ramose or ramoso-lobate margin. 

 *\. M. alcicornis. *3. M. pumila. 

 *2. M. ramosa. *4. M. tortuosa. 



II. Lamellate or glomerate incrusting, never digitate or ramose. 

 *5. M. plicata. *7. M. squarrosa. 

 *6. M. complanata. *8. M. platyphylla. 



1. Ramosa, sape lamellate, et supra ramoso-lobatce. 



1. MlLLEPORA ALCICORNIS. (Pallas.} 



M. grandis, sublamellata, basi incrustans, frondibus crassis, multifidis, 

 laciniato-palmatis, et scepe valde subdivisis sen ramosis, ramulis sub- 

 acutis, superficie levi. Coralli cellis majusculis, numerosissimis. 



Large, sublamellate, incrusting at base, fronds stout, multifid, laci- 

 niato-palmate, and often much subdivided or ramose, branchlets 

 subacute; surface smooth. Corallum having the cells rather large, 

 and very numerous. 



West Indies. 



It is probable that more than one species have been here included 

 by authors. The true alcicornis appears to be distinguished by grow- 

 ing in erect subdivided plates, having the margin digitate, or some- 

 what ramose. Instead of plates there are sometimes broad coalescing 



