800 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Middle Jacksonian (Castle Hayne limestone) : Wilmington. North Carolina 

 (common). 



Cotypes.~C.At. 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. 



Measwreme nts. 



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 Hornera subannulata Philippi, 1843, and H. 

 hippohjta Def ranee, 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) : Chipola Kiver, east of 

 Marianna, Jackson County, Florida (very rare). 



Holotype.C&t. No. 65331, U.S.N.M. 



HORNERA POROSA Stoliczka, 182. 

 Plate 145, figs. 4-19. 



1862. Hornera porosa STOLICZKA, Oligocene Bryozoen von Latdorf in Bernburg, Sitzuugs- 

 berichte der k. Aknderuie 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 



