154 PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



septa, usually 6 well-developed secondaries, and a pseudocolumella, it resembles 

 M. verrucosa, but the papilla; of the latter species have not the tendency to irregular 

 fusion and more definitely occupy intercalicular areas. 

 Distribution. — Red Sea; Amboina; Fiji Islands. 



Montipora spumosa (Lamarck). 



Plate 63, figures 2, 2a, specimen from Cocos-Keeling Islands. 



1897. Montipora spumosa Bernard, Cat. Montipora, p. 71, plate 8, fig. 1; plate II; plate 32, fig. 16. 

 1907. Montipora spumosa Bedot, Madreporaires d'Amboine, p. 277, plate 48, figs. 267-270. 



It does not seem necessary to repeat descriptions of this species. 

 Habitat and color, Cocos-Keeling Islands. — Dr. F. Wood Jones states: 



"Rough water, barrier north of Pulu Bras and the barrier on southern side of the atoll. 

 Abundant, usually yellow or brown in color." 



Distribution. — Cocos-Keeling (previously reported by Bernard); Lacepede 

 Island, Northwest Australia; Rocky Island, Great Barrier Reef; Tongatabu. 



Montipora elschneri new species. 

 Plate 64, figures I, \a, specimen from Fanning Island. 



The description of this species follows: 



Corallum an irregularly shaped, thick plate. The horizontal dimensions of the type 

 are about 90 by 93 mm.; thickness ranges from 16 to 35 mm. Usually there is no free edge. 

 The older part of the corallum had mostly been killed, and regenerated living tissue had 

 incrusted it. The surface is irregularly undulate, with small depressions and low elevations. 



Calices from 0.5 to 1.0 mm. in diameter, between 0.6 and 0.7 mm. the usual diameter. 

 The primary septa well-developed, the directives meeting and forming a more or less plug- 

 like columella, which is deep-seated. The other primary septa appreciably smaller, but 

 they sometimes extend to the columella. The secondary septa are much smaller than the 

 primary, but they are usually distinct in at least three systems, and often the cycle is com- 

 plete. Corallite walls distinct. 



The calices present three conditions in their relations to the coenenchymal surface. 

 The intervening coenenchymal surface may be flat, when the distance between the calices 

 is from 0.5 mm. in depressions to 1.5 mm. on areas which are not depressed. In some areas, 

 which are relatively small, the ccenenchyma rises beyond the calicular rims and produces 

 foveolate calices. In other areas the ccenenchyma forms papillae between the calices. 

 These are low and their sides slope upward to the apex; often they neatly fill an intercalicular 

 space and have a basal diameter of about 2 mm. Sometimes 3 or 4 papillae fuse and form 

 series up to between 5 and 6 mm. long. Occasionally a calicular opening has been carried 

 upward by the upward growth of ccenenchyma on all its sides, but the coenenchymal surface 

 is not of the same height all around the calice. This species is one of the group which Bernard 

 characterizes as " Papdlae irregular." 



The coenenchymal surface is reticulate, delicately spinulose in places, with fine costal 

 markings. 



Locality. — Tanning Island (Carl Elschner, collector). 



Type: U. S. National Museum. 



Bernard places the following IO species in the group to which M. elschneri 

 belongs, viz, M. venosa (Ehr.), M. spumosa (Lam.), M. cenigmatica Bernard, M. 

 brueggemanni Bernard, M. lanuginosa Bernard, M. flammans Bernard, M. lobulata 

 Bernard, M. edwardsi Bernard, M. acanthella Bernard, and M. fungiformis Bernard. 

 M. venosa and M. spumosa have already been considered. Of the others the follow- 

 ing have calices between 0.5 and 1.0 mm. in diameter: M. lanuginosa, M. lobulata, 

 M. edwardsi, and M. acanthella. M. lanuginosa has an "explanate, thin, translu- 

 cent" corallum; M. lobulata forms an irregularly lobate mass; M. edwardsi forms 

 "tufts of columns rising vertically from an irregular platform"; and M. acanthella 



