AI-FINITTES OP THE GENUS MADEEPOEA. 359 



express accurately the precise modes of budding to which they 

 are applied, and it would probably have been better had Eidley 

 employed the botanical terms " determinate " and " indeterminate" 

 to express the distinction in the case of branching species. In 

 foliate species of Montipora the budding is centrifugal not cen- 

 tripetal, seeing that new corallites are added at the periphery. 

 In branched specimens of Madrepora the buds arise around and 

 are indirectly connected with an elongate corallite forming the 

 axis of each branch and extending from its point of origin to the 

 apex, where it always projects more or less. This corallite, often 

 spoken of as the parent corallite, is usually o£ larger diameter 

 than the others and often exhibits a better-developed series of 

 septa. It is usually termed the apical corallite ('' Endkelche," by 

 the Grermans), but axial corallite seems much more appropriate ; 

 the part of it which is " apical " and recognizable in surface view 

 is only an insignificant part of its whole length. Eor similar 

 reasons I proj)ose to replace the term " lateral " corallite by 

 "radial" corallite, excepting in the rare instances when these are 

 arranged in lateral series on a flattened branch. 



Although the types of budding indicated by Eidley form an 

 essential distinction between Madrepora and Montipora, the type 

 characteristic of Madrepora is confined to branches formed by 

 the living colony during its growth : in other situations the buds 

 are formed in a similar manner to those of Montipora. In 

 specimens which form incrustations, — and all are incrusting in 

 the first instance — new corallites are added peripherally from an 

 undifterentiated mass of tissue which projects beyond existing 

 corallites. It is only when certain of the corallites increase in 

 length and thickness, so as to indicate the first formation of 

 branches,^ by the development of buds around them, that the 

 form of budding characteristic of Madrepora comes into oper- 

 ation. Frequently both types of budding take place at the same 

 time in one colony ; the one leads to branch forroation, the other 

 to marginal or basal extension. One not infrequently meets 

 with specimens in which a colony of a younger generation forms 

 an incrustation over the branches of a dead colony of the same 

 species. In such cases new corallites are added form a marginal 

 mass of undifferentiated tissue until the apex of the dead branch 

 is reached, and only later, when independent growth begins, is 

 the mode of budding changed. It also seems probable that the 



LINN. JOITElSr. — ZOOLOGY, VOL. XXIV. 28 



