on the Genus Paleeacis. 221 
Loe, and Horizon. Combe Hill, Henbury, near Bristol, in 
the upper beds of the Lower-Limestone Shales (8. G‘. Perce- 
val) ; Hook Point, Wexford, in the Mountain Limestone (De 
Koninck). 
Other Localities. Nauvoo, [linois, in the Keokuk division 
of the Subcarboniferous (Week and Worthen) ; Dallas city, in 
Carboniferous Limestone (Von Seebach). 
Paleacis cyclostoma, Phillips. 
Hydnopora? cyclostoma, Phill. Geol. Yorksh. 1886, ii. p. 202, pl. 2. 
aes 
Propora? cyclostoma, Edwards and Haime, Polyp. Foss. Terr. Pal. 
1851, p. 225; id. Mon. Brit. Carb. Corals, 1852, p. 152. 
Sphenopoterium enorme, Meek and Worthen, Proc. Acad. Nat. Sci. 
Philad. for October, 1860, p. 448; id. Illinois Geol. Surv. Rep. 
1866, ii. p. 146, pl. 14. f. 1, a, 2. 
Sphenopoterium enorme, var. depressum, Meek and Worthen, Illinois 
Geol. Surv. Rep. 1866, ii. p. 146, pl. 14. f. 2, a, b. 
Ptychochartocyathus lacus, Ludwig, Paleeontographica, 1866, xiv. pp. 189, 
231, pl. 47. f. 14, pl. 69. f. 2, a. 
Paleacis enormis, Von Seebach, Nachr.k. Gesellsch. Wissensch. zu Gott. 
for 1866, p. 243; id. Zeitschr. deutsch. geol. Gesellsch. 1866, xviii. 
p- 309. 
Paleacis laxa, Kunth, Zeitschr. deutsch. geol. Gesellsch. 1869, xxi. 
p. 185, pl. 2. f. 2. 
Paleacis compressa, De Koninck, Nouv. Rech. Anim. Foss. Terr. Carb. 
Belgique, 1872, 1° pt. p. 158, pl. 15. f. 7 (aon Meek and Worthen). 
Paleacis cyclostoma, De Koninck, Nouv. Rech. Anim. Foss. Terr. Carb. 
Belgique, 1872, 1* pt. p. 159, pl. 15. f. 8; R. Etheridge, Jun., Mem. 
Geol. Surv. Scotl. no, 82. p. 97. 
Spec. char. Colony simple or composite, subglobose or 
obtusely subturbinate, usually depressed, composed of a large 
number of cells (from one to twelve observed), assuming a 
bi-, trilobate, quadrangular, or multilobate character, usually 
more or less developed on the same plane, but occasionally 
becoming superimposed, attached to foreign bodies ; and in one 
well-marked variety they become cuneiform and irregular, or 
elongate and partly free. Base of attachment large and trun- 
eate, flat or variously grooved according to the body to which 
the colony is fixed, and raised into well-marked, thick, 
concentric wrinkles or ridges. Cups open, contracting but 
little, moderately deep, ornamented internally with a large 
number of small pseudo-ridges, consisting of closely-set micro- 
scopic granules or prickles, which in some cases increase 
towards the margin of the calice by bifurcation ; cup-margins 
circular or oval, with usually well-developed elevated free 
edges, separated from one another by intervening depressions 
of variable breadth ; cup-floors broad, covered with numerous 
irregularly disposed prickles similar to those forming the so- 
called septal ridges. External surface ornamented with finely 
