﻿TUBERCULATE MONTIPOR^. 147 



edges ; (3) a tendency to form tufts (open or close) of cylindrical branches encrusting the tubes 

 of commensal worms ; (4) the tubercles form plates at all angles with one another, especially 

 upon the branches due to the commensal worms. I feel, therefore, justified in making this 

 provisional group under the specific name cffusa, Dana's species having shown all the above 

 characters. That the grouping is purely provisional, the differences in the calicles and in 

 the tubercles themselves abundantly prove. 



a. Persian Gulf. A. S. G. Jayakar, Esq. 92. 1. 13. 7. 



&. Diego Garcia. G. C. Bourne, Esq. 91. 4. 9. 43. 



c. Aden. Major Yerbury. 87. 12. 11. 16. 



d. Aden. „ „ 87. 12. 11. 11. 

 «,/. Eocky Island, Great Barrier Eeef. CoU. Saville-Kent. 92. 12. 1. 261, 264. 



g. Palm Islands, Great Barrier Eeef. „ „ 92. 12. 1. 6. 



A. Locality not recorded. ? 



i. Aden. Major Yerbury. 87. 12. 11. 13. 



?/ Tongatabu. J. J. Lister, Esq. 



123. Montipora frondens. 



Description. — Corallum, complete form unknown, free-growing edges divided into distinct 

 lobes, which curve upwards, the lateral edges of one lobe may overlap the adjoining. These 

 lobes are unsupported by any epitheca, and thick, 2 to 3 mm. at the outermost edge and 

 rapidly thickening ; older and more central region being 3 cm. tliick at 5 cm. distance from the 

 outermost edges of the lobes. The thickening portion is in tiers, showing layers of different 

 growths often separated by deposits of sediment. From this central region thick irregular 

 knobbed processes rise as high as 3 • 5 cm. 



Calicles deep, not conspicuous, • 75 mm., very irregularly distributed, scattered or closely 

 crowded. Primaries reach beyond the half radius circle ; indications of secondaries. One 

 directive often specially conspicuous. When the calicles are surrounded by tubercles the 

 septa begin to appear on the sides of these latter, the directive septa being the highest and best 

 developed. The margin is not sharply defined, the interseptal loculi being open to the deep 

 interstitial fissures. On the under surface, minute star-like calicles open in the coarse flaky 

 reticulum, like small irregular punctures in the surface. They are largest and most con- 

 spicuous near the growing edges. 



The coenenchyma shows the typical streaming layer, expanding upwards and downwards 

 into glassy threads. Towards the under surface these are often extremely fine, but are joined 

 by thick and solid junctions. The reticulum of the upper layer is coarse, and its vertical 

 elements are irregularly thickened and nodulated but hardly differentiated into trabeculae. 

 On the surface these more vertical threads may rise up as tubercles arranged in nearly regular 

 rings round the calicles, the interstices being concavely depressed, and consisting of a nearly 



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