74 



PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



base, above which they diverge, subdivide, and often interfuse. The following table, 

 which shows the measurements of branches of Seriatopora hystrix, indicates the 

 relative attenuation: 



Measurements of branches of Seriatopora hystrix. 



The measurements indicate very gradual decrease in diameter and that the 

 apices are short conical or even obtuse (see plate 20, figs, \a-\c). The arrange- 

 ment and size of the calices are adequately shown in the figures. The calicular 

 margins are slightly elevated, less prominent on the lower side of the calice. 

 Six septa are obvious, the directives strongly developed. The columella is promi- 

 nent, compressed in the plane of the directives. Ccenenchyma dense, surface finely 

 echinulate. 



The specimen on which the preceding description is based was collected 980 

 feet from shore. Specimens farther out on the flat show some variation, probably 

 induced by rougher water. 



Stations, Murray Island. — Southeast reef, line I : 



650 feet from shore, rather loosely branched, fragile. 

 800 feet from shore, spreading clump, fragile. 

 980 feet from shore, spreading clump, fragile. 

 1,000 feet from shore, branches of about usual thickness but somewhat more crowded, much coalesced, mak- 

 ing a stronger structure than in the colonies nearer shore. 

 1,200 feet from shore, (a) branches rather short, divergent, corallum fairly strong, (b) branches thinner, 



corallum fragile. 

 1,400 feet from shore, branches rather short, very crooked, with many aborted branchlets, environment 

 evidently unfavorable. 



Distribution. — Fiji Islands (type); Amboina (Bedot); Murray Island, Australia. 



Seriatopora angulata Klunzinger. 



Plate 20, figures 3, 4. 



1879. Seriatopora angulata Klunzinger, Korall. Roth. Meer., pt. 2, p. 73, plate 10, fig. 14. 



1906. Seriatopora angulata von Marenzeller, Denksch. k. k. Akad. Wiss. Wien, vol. 80, p. 78, plate 28, 



figs. 107-112; plate 29, figs. io7<2-ii2u, 115. 

 1910. Colorless Stylophora Wood Jones, Coral and Atolls, p. 97, text-fig. 31. 



As von Marenzeller has so fully considered this species, a redescription is 

 superfluous. 



Habitat, etc., Cocos-Keeling Islands. — Dr. Wood Jones has submitted two speci- 

 mens which show variation in response to habitat. He makes the following notes: 



Specimen with attenuate branches (plate 20, fig. 3), "lives only in the lagoon, appears 

 to be altogether absent from the barrier or any water at all rough; depth 4 to 5 fathoms; not 



