DESCRIPTIONS OF SPECIES. 143 



The specimens upon which the species is based were sent to nie for 

 description by Dr. J. C. Merriam, of the Univex'sity of Cahfornia, and it is 

 with pleasure that the species is named for him. 



The generic determination of this species is in one respect doubtful, i. e., 

 the septal margins could not be studied, because of the worn condition of the 

 surface of the specimens. The material is not well enough preserved to 

 permit the microscopic details to be ascertained. In the cross section of some 

 septa there are faint indications of rather large trabecule, similar to the 

 trabeculse of Favia fraguni (Esper) ( z: ananas auct. non Linn.) of the JWest 

 Indies. What evidence is afforded by the sections of the septa supports the 

 opinion that the septal margins are dentate. All of the other characters are 

 typical for Favia; therefore there is very little reason for doubting tlie 

 generic reference. 



Geuus HAIMESIASTR^A gen. nov. 



HaimesiastriBa conferta sp. iiov., type species. PL XV, tigs. 6 to 9; P]. XVI. all 

 figures. 



Principal macroscopic characters. — Colouy massivc. Or ramous. CoralHtes in the 

 central portion of the colony united directl}- by their walls, by their costse, 

 or by exotheca. Calicular margins very slightly elevated. Septa in three 

 cycles, six systems ; twelve reach the columella space ; margins entire, sur- 

 faces smooth. Endothecal dissepiment abundant. Corallite cavities not fill- 

 ing up. Columella false, formed by the fusion of the internal margins 

 of the first two cycles of the septa. Budding between the corallites. In the 

 central portion of the colony, where the corallites are more or less crowded, 

 there is no ccieuenchyma, but as the corallites pass outward they diverge, 

 and a deposit of coenenchyma begins. In young branches the coenenchyma 

 is often slightly vesicular, containing some exotheca, but in the outer por- 

 tions of old branches it is almost or entirely solid. (_)n the weathered end 

 of a branch it shows a concentric structure. Its outer sm-face is granulate, 

 and in addition thereto is marked by costse corresponding to all cycles of septa. 



MICROSCOPIC STRUCTURE. 



The specimens are not so good as is desirable for a very accurate 

 study of the microscopic features, chemical changes in many having olilit- 

 erated the minute details. 



The septa. — As already stated, the septal edges are entire and the faces are 

 smooth. The only ornamentation of the septal faces are undulations that 



