﻿126 MADEEPORAEIA. 



interstitial spaces as very delicately feathered tubercles, which are nevertheless fairly sharply 

 outlined to the naked eye. The six trabecula3 which give rise to the septa form a close 

 protuberant ring round the calicles. On the under surface the tubercles surrounding the 

 calicles may fuse into thick, iinely echinulate rings ; this is especially the case where the 

 calicles are somewhat far apart, elsewhere calicles may rise as hemispherical eminences, or 

 again be all level with the surface. 



Manopora lichen is Dana's second species of his division of the genus characterised by 

 " tubiform calicles." His iirst species {gcminulata) has been shown by Verrill to be a true 

 Turbinarian, and some doubt attaches to the other two also, because protuberant calicles are 

 certainly rare in this genus. (See, however, M. stalagmites, and Introduction, p. 10.) 

 There are three specimens from Eodriguez in the National Collection labelled Montipora 

 lichen Dana, by Briiggemann, Dana's original tyjae being apparently from Tahiti, Society 

 Islands. With these I have associated, with much hesitation, three specimens from the Great 

 Barrier Eeef 



These sbc specimens, forming a most unsatisfactory group, are united primarily by one 

 common feature. They all show close rings of tubercles round the calicles, which, to the 

 naked eye, look lilve protuberant walls. Tliis character occurs also in M. foliosa and 

 M. solanderi, but in them it, as a rule, appears only irregularly, sometimes apparently as a 

 transitional stage in the thickening of the corallum, a little way below the growing edge. 



Two of the Rodriguez specimens are peculiar in being flat portions of corroded stocks, the 

 edges of which have been regrown over above and below, the creeping edges tending every- 

 where to turn up ; both the calicles and the tubercles are a little larger than are those of the 

 Australian specimens. 



These latter form another group not differing more from one another than do the three 

 Eodriguez specimens. The grouping, however, can only be provisional. The finer shades of 

 difference between these tuberculate Montipores are extremely puzzling, and only examination 

 of long series could give one confidence in dealing with them. Unlike the Eodriguez specimens 

 with their encrusted margins, these are explanate with thin edges sloping upwards. The under 

 surface shows, however, the same tendency to proliferate and to form irregular knobs, &c. ; 

 many of the calicles of the under surface are also protuberant upon hemispherical elevations ; 

 the origin of these walls from tubercles is, however, obscured. On specimen d the tubercles 

 are smaller and very crowded. On e the tubercles are larger and not so sharply outlined ; 

 the calicles upon the sloping sides are markedly nariform, the aperture being greatly tQted 

 towards the growing edge, and sometimes with no more than one large tubercle sloping 

 outwards over it. Specimen / is a fragment broken from the thin edge of a coral which 

 evidently closely resembled e. 



In all the specimens the surface is very uneven, owing to the tendency of tubercles here 

 and there to grow up and carry single large calicles above the rest. 



a, h, c. Eodriguez. Eoyal Society. 



d. Thursday Island, Great Barrier Eeef. CoU. SaviLle-Kent. 



e,f. Adolphus Island. „ „ 



