800 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Middle Jacksonian (Castle Hayne limestone) : Wilmington. North Carolina 
(common). 
Cotypes . — Cat. No. 65329, U.S.N.M. 
HORNERA TENUIRAMA, new species. 
Plate 144, figs. 14-23. 
Description— The zoarium is formed of small rami , round, and much branched, 
on which the zooecia leave little place for the dorsal. The tubes are invisible 
exteriorly; they bear two or three longitudinal sulci, at the base of which there 
are two or three vacuoles. The peristome is somewhat salient, thick, orbicular. 
The dorsal is very narrow; it bears some longitudinal sulci with vacuoles of the 
same size as the frontal vacuoles. 
Diameter of the peristome 0.10-0.12 mm. 
Measurements. — Diameter of the aperture 0.06 mm. 
Distance between the peristomes 0.40 mm. 
Variations and affinities. — In the frequent annular arrangement of the peris- 
tomes, this species much resembles Iiornera subannulata Philippi, 1843, and II. 
hippolyta Defrance, 1831. It differs from them in the considerable reduction of the 
dorsal, which is extremely narrow and which is not always easy to discern. 
Occurrence. — Middle Jacksonian (Castle Hayne limestone) : Wilmington, 
North Carolina (very common). 
Cotypes . — Cat. No. 65330, U.S.N.M. 
HORNERA TUBEROSA, new species. 
Plate 145, figs. 1-3. 
Description . — The zoarium is erect, of compressed and bifurcated branches. 
The tubes are invisible exteriorly ; they bear a very wide, longitudinal sulcus with 
a single vacuole. The peristome is salient, thin, orbicular. The dorsal is convex ; 
the longitudinal sulci are rather deep ; the vacuoles are very small ; the nervi 
are wide, convex, and bear numerous salient tuberosities. 
Affinities. — This species is very well characterized by its dorsal tuberosities, 
this character never having been observed in any other known species. The only 
specimen found has been figured, but it is very characteristic. 
Occurrence . — Upper Jacksonian (Ocala limestone) : Cliipola River, east of 
Marianna, Jackson County, Florida (very rare). 
Holotype. — Cat. No. 65331, U.S.N.M. 
HORNERA POROSA Stoliczka, 1862. 
Plate 145, figs. 4-19. 
1862. Horncra porosa Stoliczka, Oligocene Bryozoen von Latdorf in Bernburg, Sitzungs- 
bericlite der k. Akademie der Wissenschaften Wien, vol. 45, Abth. 1, p. 79, pi. 1, 
fig. 3. 
Description. — The zoarium is formed of compressed branches bearing rami 
almost opposite. The tubes are invisible exteriorly; they bear two oblique sulci 
