364 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



(125 meters). Some of the specimens are nearly wldte in color, bnt 

 most of them are of the reddish color characteristic of the species. 



Genus HOMOTREMA Hickson, 1911. 



This genus has been separated by Hickson from Polytrema on the 

 basis of the structure of the test. The Philippine material carries 

 out the points of structure which he discusses in the fullest manner. 



The following is the generic description given by Hickson: 



The surface is marked by clearly defined areolae about 0.1 mm. in diameter, per- 

 forated by a large number of small foramina, 0.001 mm. in diameter. The boundaries 

 of the areolae are solid, and there are no pillar pores. Below the surface there may be 

 seen a number of chambers communicating with one another by large open passages 

 and bounded by solid walls. There are no hollow pillars and no foramina except 

 those on the outer walls of the superficial chambers. 



HOMOTREMA RL'BKUM (Laniarck). 



Millepora rubra Lamarck, Anim. sans Vert., vol. 2, 1816, p. 202. 



Polytrema rubra Carpenter, Parker, and Jones, Introd. F'oram., 1862, p. 235, 

 pi. 13, figs. 18-20. 



Homotrema ruhrum Hickson, Trans. Linn. Soc. London, Zoology, vol. 14, 1911, 

 p. 454, pi. 30, fig. 2; pi. 31, fig. 9; pi. 32, figs. 19, 22, 28.— Heron-Allen and 

 Earland, Trans. Zool. Soc. London, vol. 20, 1915, p. 729. 



The Philippine material, although occurring at a few stations as 

 far as the available material shows, is very characteristic, having the 

 form and the deep red color as well as the finer structure of the spe- 

 cies, as suggested by Hickson. The records include the following 

 four stations: D5109, China Sea off southern Luzon, 10 fathoms (18 

 meters); D5136, vicinity of Jolo, 22 fathoms (40 meters); D5146, 

 Sulu Archipelago off Siasi, 24 fathoms (44 meters); and D5179, off 

 Rombion, 37 fathoms (68 meters). 



Homotrema ruhrum — Material examined. 



