Scleractinian Corals WELLS 
287 
Type species: Oryzotrochus stephensoni n. sp. 
Oryzotrochus stephensoni sp. nov. 
Figs. 1-5 
With the characters of the genus as diag- 
nosed above. Septa 12 in number, in two 
cycles, thin, upper margins evenly arched and 
equally exsert over the wall and dropping 
steeply to level of the columella about half- 
way between wall and axis. Septa generally 
all extending to and fusing with the colu- 
mella, but secondaries in one or two systems 
may join primaries short of the columella. 
Costae corresponding to all septa, equal, high, 
smooth -margined, separated by relatively 
broad and flat interspaces. An irregular row 
of very small buttresslike expansions on each 
side of each costa at junction with the wall. 
Primary costae distinct to the base; secondary 
costae arising just short of the base. Columella 
a slender style elevated about to height of 
exsert septal margins. 
Dimensions 
HEIGHT 
Holotype 3.5 mm. 
Paratype 3.0 
Paratype 3.3 
Paratype 2.4 
CALICULAR 
DIAMETER 
1.7 (Figs. 3, 4) 
1.5 (Fig. 5) 
1.6 (Fig. 1) 
1.5 (Fig. 2) 
Named for W. Stephenson, Professor of 
Zoology, University of Queensland. 
Holotype and figured paratypes to be de- 
posited in the U. S. National Museum. Re- 
maining paratypes are in the Australian 
Museum. 
Locality 
Murray Islands (9°55'S., 144°02'E.), near 
northern end of Great Barrier Reef, Queens- 
land, 9-15 meters. 
Part II. A New Species of Turbinaria from the Great Barrier Reef 
At least 350 species representing 57 genera 
of reef-building scleractinian corals are now 
known from the Great Barrier Reef area 
(Wells, 1955: 21). It would seem ungracious 
to add a new species to this burdensome 
total, especially to a genus with 34 species 
already reported from this region, many of 
them of doubtful validity, but the form de- 
scribed below is so distinct that it cannot be 
referred to any known species of Turbinaria, 
Family DENDROPHYLLIIDAE 
Genus turbinaria Oken 1815 
Turhinaria heronensis sp. nov. 
Figs. 1-4 
Corallum bushy, to 20 cm. in height, 
formed by erect branches arising from a small, 
encrusting base. Corallites tending to develop 
irregularly on opposite sides of flattened and 
twisted branches, new extratentacular buds 
appearing in the plane of the branches be- 
tween the previously formed and the next 
previously formed corallites. Corallites cylin- 
drical, rarely more than 10 mm. long without 
buds, averaging 4 mm. in diameter. Wall 
spongy. Calices deep (3 mm.), circular, aver- 
aging 3 mm. in internal diameter. Septa thick 
peripherally in the wall, thin axially, upper 
margins dropping abruptly to the level of the 
columella, 36 to 40 in number, irregularly 
arranged, with 24 to 30 extending to the 
columella, the remainder fusing to lower cy- 
cles of septa. Columella a deep, chicoraceous, 
trabecular column about half the internal di- 
ameter of the corallites. Coenosteum and ex- 
terior of free parts of corallites very compact 
but porous, the surface appearing smooth, 
but very finely vermiculo-echinulate. 
This species is readily distinguished from 
practically all other known recent species of 
