Indo-Pacific Scleractinian Corals, 4: Stylo coeniella guentheri — Wells 
205 
into a prominent, thickened, laterally striated 
and granulose spine (Figs. 4, 5, and 10), the 
external base of which may carry up the spinose 
coenosteum. The second cycle of septa is weakly 
developed, each septum consisting of a row of 
fine trabecular spines projecting nearly hori- 
zontally inward from the wall and extending 
about a quarter of the distance to the axis. 
Columella a prominent solid style rising to the 
level of the calice rim or slightly exsert (Figs. 
5 and 8 ) . 
The encrusting rather than ramose growth 
habit and dentate septa easily distinguish this 
species from Stylophora, but otherwise it has all 
the characters of that genus: small corallites, 
few septa, styliform columella, spinose vesicu- 
lar, tabular, or solid coenosteum, and styliform 
effusions from one of the primary septa (more 
columniform in S. guentheri than the "hoods” 
of Stylophora ) . The dentation of the septa is 
perhaps the most important difference, although 
the primary septa of Stylophora may show 
traces of such structures, and S. guentheri is best 
placed in Stylocoeniella next to the type species 
S. armata, with which it shares the same growth 
form, styliform septal proliferations, and occur- 
rence as inconspicuous patches on reefs and 
shallower parts of lagoons. In S. armata 2 (Fig. 
11; see also Yabe and Sugiyama, 1935: Pi. 15, 
and Wells, 1954: Pi. 96, figs. 1-4) the calices 
are larger (0.75-1.25 mm), more nearly ceri- 
oid than plocoid, the 6 septa of the second 
cycle are more completely developed, frequently 
2 In addition to the previously reported occurrences 
of this species cited by the writer (1954:410; 1955), 
subsequent collections indicate its presence in Saipan, 
Ifaluk Atoll ( Caroline Islands ) , Eniwetok and Arno 
Atolls (Marshall Islands), and Zamboanga (Philip- 
pines). 
nearly equal to the first cycle, and the trabecular 
dentation on the inner end of each primary sep- 
tum adjacent to the columella is often large and 
paliform. 
The fragmentary fossil specimen from the 
Miocene of Eniwetok recently referred by the 
writer to Stylocoeniella is indistinguishable from 
S. guentheri in all respects except for the 
slightly larger (1 mm) calices. 
HOLOTYPE: British Museum (N.H.) No. 
1889.9.24.84:58 m, Macclesfield Bank, China 
Sea. 
DISTRIBUTION: Miocene (?) (Eniwetok). 
Recent: Macclesfield Bank, 40-58 m; lagoon, 
4-40 m, Eniwetok Atoll; lagoon reef slope, 6- 
26 m, Gan I., Addu Atoll (Maidive Islands). 
REFERENCES 
Bassett-Smith, P. W. 1890. Report on corals 
from the Tizard and Macclesfield Banks, 
China Sea. Ann. Mag. Nat. Hist. (6), 6:353- 
374, pis. 12-14 (maps). 
Wells, J. W. 1954. Recent corals of the Mar- 
shall Islands. U. S. Geol. Surv. Prof. Paper 
260-1:385-486, pis. 94-187, figs. 119-122, 
4 tables. 
— 1955. A survey of the distribution of 
reef coral genera in the Great Barrier Reef 
region. Repts. Great Barrier Reef Committee 
6:21-29, chart. 
1964. Fossil corals from Eniwetok Atoll. 
U. S. Geol. Surv. Prof. Paper 260-DD: 1 101— 
1111, pis. 296-300, table. 
Yabe, H., and T. Sugiyama, 1935. Stylocoen- 
iella, a new coral genus allied to Stylocoenia 
and Astrocoenia. Japanese J. Geol. Geog. 12: 
103-105, pi 15. 
