28 MCMURKRICH. [Vou. III. 
5. Aulactinia stelloides,n.sp. (Pl. 1, Figs. 5-6; Pl. IIL, Figs. 
8-10.) 
This form was found usually buried up to the tentacles in the 
sand in tidal pools, but also not unfrequently on the under sur- 
face of blocks of coral rock along the shore in shallow water. 
In color the column (PI. I., Fig. 5) is brown, darkening above, 
and pale, and, in some cases, almost colorless below, the lines of 
the insertions of the mesenteries being usually evident. The 
verrucz, on the upper part of the column, are pale, almost 
white. The tentacles are brown, or almost cream-colored, and 
are banded or mottled upon their inner surfaces with white, 
which sometimes varies to olive-green. Disc (Pl. I, Fig. 6), 
olive-green, with a zig-zag band of white about midway between 
the bases of the tentacles and the mouth. Ina small specimen 
the tentacles were almost white, their mottlings being opaque 
white, and in this case the disc also was almost white, with only 
a faint indication of green. 
The base is rather strongly adherent and somewhat larger 
than the column, measuring about 1.3 cm. in diameter. The 
column is cylindrical, measuring in the fresh condition 1.7 cm. 
in height and 1.1 cm. in diameter; in the largest of the pre- 
served specimens these measurements are about 0.8 cm. and 
I. cm. respectively. The lower portion is smooth, while the 
upper one-third is provided with vertical rows of verrucz, to 
which particles of sand, etc., adhere. The upper verrucz are 
more prominent than those lower down, the marginal ones 
being the largest of all, but showing no indications of lobation. 
Structurally the verrucz are elevations of the entire column 
wall, the ectoderm, mesogloea, and endoderm being, as it were, 
blown out at certain spots to form hemispherical elevations 
(Pl. III., Fig. 8). The mesogloea, in the centre of the verruce, 
is quite smooth on both surfaces, but around the margin its 
endodermal surface is raised into rather strong finger-like pro- 
cesses (mp), covering which are the endodermal muscle cells. 
The ectoderm of the central portion (mec) is markedly different 
from that found at the margins and on the column wall gener- 
ally; it is composed apparently altogether of exceedingly fine, 
almost filiform cells, there being none of the claviform gland 
cells elsewhere abundant, and apparently no “stutzzellen.” It 
is difficult to separate these cells from the mesogloea by macera- 
