﻿PAPILLATE MONTIPOE^. 79 



The series referred to shows two extremes of growth. Small fan-shaped fronds, 3 to 4 mm. 

 thick, rise upon thin stalks in close clusters and fuse indiscriminately, their expanded portions 

 being twisted and bent in all directions ; from the edges of the fans papillate processes rise, 

 so that each looks not unlike a cockscomb; In the other extreme, the cluster is so compact 

 that the fans are no more distinct, but merely their stalks rise like columns supporting a 

 solid mass, the top of which rises into coenenchymatous papillae. One cause of this difference 

 in growth appears to be the number of foreign organisms, sponges, &c., which keep the cluster 

 loose and open. The specimen in the National Collection may, I think, be provisionally, 

 regarded as another growth-form of this same coral, which, failing any evidence that it really 

 is M. multilobata, I have called ML edwardd; the chief difference to be noted being the- 

 character of the papillse, which were large and round topped in the Paris specimen,, but are 

 here narrow and swollen as if scLueezed up between the narrow interstices. 



a. Eed Sea. [Eegister No- 97. 9:25; 2>.] (Type.) 



[Cf. the mode of growth of M. alveojgova, described in the Appendix.] 



59. Montipora acanthella. (PI. XII. fig. 1; PI. XXXIH. fig. 2.) 



Description. — Corallum encrusting, with free drooping outgrowths, the edges of which 

 curve upwards and, in bending, are crumpled into small irregular folds. The upper surface 

 of the coral is thrown up into jagged processes of all sizes which may grow out in any 

 direction. Eepeated encrustations of suchi an uneven surface make the whole stock very 

 irregular. The growing edges are 3 mm. thick and generally deeply pitted with numerous 

 young calicles. The epitheca is very irregularliy developed. 



Calicles small, • 50 to • 75 mm., inconspicuous, evenly distributed, about 1 mm. apart. 

 Septa variable, either six well developed primaries crossing the half radius circle with only 

 faint traces of a second cycle, fossa inconspicuous, or else primaries short with secondaries 

 distinct and fossa conspicuous. Stout directives are generally present. The calicles on the 

 under surface are sUghtly smaller and closer together. 



The streaming layer of the coenenchyma is a dense and coarsely filamentous reticulum ; 

 the lower thickening layer is still more dense, whUe the upper layer rises irregularly into 

 sharp ridges and papillae. The larger papillate ridges throw out from their sides secondary 

 ridges and papillae also with sharp edges and points ; hence the jagged outgrowths mentioned 

 above. The under surface is smooth, and smooth pendent knobs covered with calicles may 

 protrude from among the epithecal and other encrusting films which cover up most of the 

 central region of the under surface. 



There is only one specimen, some 24 cm. in long diameter ; the stock is creeping over a 

 dead and corroded previous growth. The coral is peculiar in the irregular distribution and 

 shapes of the papillae, and in the jagged processes which grow out of them by the secondary 

 budding of young calicles from their surfaces, accompanied by secondary formation of sharp 

 ridges or papillate points. 



a. Locality not recorded. [Eegister No. 97. 5. 18. 7.] (Type.) 



