
ROTALIIDAE—ROTALIA; HOMOTREMA. 53 
usually without ornamentation, is the same as that found in the 
more temperate regions. D’Orbigny does not figure this form in 
his Cuban monograph. It was not widely distributed in the Tor- 
tugas region, being found at but three stations, two of them in the 
moat at Fort Jefferson, in warm, shallow, stagnant water. The 
other station was on Long Key, under similar conditions. It seems 
strange that this species, which is so abundant under these conditions, 
should not occur at any of the stations in deeper water. This would 
tend to show that this form is perhaps distinct from the ordinary 
R. beccarii. 
Genus HOMOTREMA Hickson, 1911. 
Homotrema rubrum (Lamarck). 
(Plate 14, Figures 6 to 8.) 
Millepora rubra Lamarck, Hist. Nat. Anim. sans Vert., vol. 2, 1816, p. 202. 
Polytrema rubra Dujardin, Hist. Nat. Zooph., 1841, p. 259.—Carpenter, Parker, and Jones, 
Introd. Foram., 1862, p. 235, pl. 13, figs. 18 to 20. 
Homotrema rubrum Hickson, Trans. Linn. Soc. London, Zoology, ser. 2, vol. 14, 1911, pp. 
445, 454, pl. 30, fig. 2, pl. 31, fig. 9; pl. 32, figs. 19, 22, 28.—Heron-Allen and 
Earland, Trans. Zool. Soc. London, vol. 20, 1915, p. 729.—Cushman, Bull. 100, 
U.S. Nat. Mus., vol. 4, 1921, p. 364. 
At one of the extreme low tides, when the 
old, dead reefs near Long Key were exposed, 
it was found that the under sides of most of 

= =..5 
Fias. 4 to 6.—Homotrema rubrum (Lamarck). 
4. A raised portion, showing the plates and the long, 
projecting lines of spicules. 
5. A more enlarged view of a younger portion, show- 
ing the relation of the plates. 
[ 6. A portion of one of the lines of spicules with the 
cementing substance in black. 
6a. A portion of the same, enlarged, showing the 
areas of cement in stipple. 


