﻿TUBERCULATE MONTIPOR^. 125 



are simply (minute) specimens of M. prolifera of Briiggemann, wliile others are small examples 

 of M. Iwia, Lam. (= M. foliosa), then the specimens here named M. minuta might well be 

 classed under the heading M. solanderi. It is clear that we have here two parallel series of 

 forms, the smaller series being in the less favourable northerly regions. I keep the two series 

 quite distinct, because we have no evidence of the relationship of the smaller forms with the 

 larger tropical forms, and also for the purposes of more exact description of the various growth- 

 forms than would be possible if I had tlirown all these small and beautifully coloured specimens 

 into the series of examples which illustrate the larger and more important types. 



The difference in the thickness of the specimens may be due to age : the thinnest (d) is a 

 complete ear or scallop-shaped stock about 5 cm. in diameter (PI. XXIII. fig. 3). It grows out 

 freely from a lateral point of attachment to some previous growth from which it appears to 

 have sprung. The other specimens are all fragments from the edges of larger stocks. Most 

 of the specimens suffer from the presence of young Balanids. 



a, h, c. Macclesfield Bank, 13 fathoms Coll. Bassett-Smith. 92. 10. 17. 137. (Types.) 



(fragments). 



d. Macclesfield Bank, 13 fathoms „ „ 



(thin young stock). 



e. Macclesfield Bank (fragment „ ^, 



distorted by Balanids). 



103. Montipora lichen. 



?Manopora lichen, Dana, Zooph. (1848) p. 492. 



Montipora lichen, Briiggemann, Phil. Trans., clxviii. (1879) p. 578. 



Description. — Corallum explanate, 5 mm. thick, siu'face more or less encrusting with free 

 " bi-facial " edges, the coral often running back over the epitheca, which thus only appears in 

 patches. 



Calicles small, • 5 mm. diameter, star-like. One or two cycles of septa. Primaries thin 

 but reaching to the half radius circle, most of the calicles surrounded by a well defined ring 

 of tubercles so as to appear as if the calicles themselves were protuberant ; groups of two or 

 three mounting together 2 to 3 mm. above the surface. Eound the growing edge the caUcle 

 apertures slope outwards, and only one or two tubercles grow out slantingly over them. 

 A side aspect of these calicles, hooded over by the tubercles, suggests the nariform calicles 

 common among Madrepores. On the under surface calicles crowded, often protuberant owing 

 to rings of tubercles of various heights and compactness. 



Coenenchyma shows in section the streaming layer. The lower threads do not thicken, 

 but, bending perpendicularly and joining together by junctions, end on the free under surface as 

 fine single points or else as well developed feathery tubercles. At a distance from the growing 

 edge the surface gets smooth and compact. The threads of the upper layer greatly thicken, and 

 form short stout trabeculse, distinct and rather far apart. These trabecul£e project above the 



