470 Prof. W. H. Dall on Hydrocorallince Srom 
Habitat. Kyska Harbour, Kyska Island, in the Western 
Aleutians; one specimen on the beach growing in a cavity 
between the layers of a mass of Nullipore, collected July 1873, 
by W. H. Dall. Museum number 6851. 
Allopora papillosa, n. s. 
Coenosteum very thin, incrusting, livid madder-pink or 
brown, with a regularly papillose surface, with close-set 
sporadic calyces composed of deep cylindrical gastropores 
vertically grooved for from three to six dactylopores, which are 
wholly continuous with the cavity of the gastropore. Am- 
pulle not noticed. Diameter of the calyx about 0-5 millim., 
of the gastropore proper about 0°35 millim. ; average distance 
between the calyces 0°7-1°3 millim. 
Gastropores deep, cylindrical, with a short, hardly percep- 
tible style, which comes into the bottom of the gastropore ; 
but, as a vertical section shows, not vertically but obliquely 
from one side. Inner surface nearly smooth, a narrow ele~- 
vated ridge bounding the margin of the combined gastropores 
and dactylopores. 
Dactyloporic grooves rather shallow, long, each with an 
evanescent trace of a style on the outer wall ; six seems to be 
the normal number to each calyx. 
General surface spiculose or finely granulated with small, 
pointed granules, with regularly-shaped, elevated, uniform 
papille: standing in the spaces between the pore-margins, and 
rising to about the same height, but absent on the immature 
growing margin of the colony. 
Coenosteum less vesicular than in the previously described 
forms. Soft parts unknown. 
Habitat. On the outside of a living Mytilus californianus, 
from 6 fathoms, Coal Harbour, Unga Island, Shumagin 
Islands; collected October 1874, by W. H. Dall. Museum 
number 6852. 
Errina Pourtalesii, n. s. 
Ccenosteum of a saccharine structure, rising in stout, sub- 
cylindrical, rather round-pointed, occasionally branching stems 
10 to 50 millim. high (possibly much larger at times), and 
8 or more in diameter; colour, when fresh, deep rose-red, 
bleaching to white or grey in dead specimens ; surface loosely 
granular, becoming lighter coloured and more compact inward 
toward the central axis; gastropores disposed in irregular 
lines, which, in the specimen in hand, have a tendency to run 
from the base spirally to the left, around the column, but are 
