378 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
HIPPOPORELLA MULTILAMELLOSA. new species. 
Plate 48, figs. 18-22. 
Desorption . — The zoarium is free and formed of many lamellae superposed 
on the same side; the base in contact with the subjacent algae presents some hexa- 
gonal zooecia striated transversely and sometimes perforated. The zooecia are 
distinct, hexagonal, separated by a very salient thread; the frontal is smooth, 
convex, ornamented with some lateral areolae. The aperture is elongated ; the 
anter is almost circular and separated by two very salient cardelles from a poster 
rectilinear exteriorly and concave interiorly. The ovicell is large, globular, salient, 
imbedded in the distal zooecia; it opens above the aperture and can not be closed 
by the operculum. The avicularium is large, transverse, without pivot ; it is placed 
on the frontal irregularly. 
Measurements. — Aperture \ha= 0.13 mm. „ . f Zis=0.50 mm. 
(exterior) 1/(2=0.10-0.11 mm. eCia Us=0.35-0.40 mm. 
Variations. — In the interior (fig. 21) the two cardelles are represented by 
two transverse condyles, somewhat salient. The avicularium is most character- 
ized by its mandible lodged in a calcified area, spatulate in form and of little depth; 
the orifices which serve as passage for the retractor and extensor muscles of the 
mandible are separated or joined together. The frontal is a compact olocvst per- 
forated simply by some lateral areolae. 
Affinities.-— In its exterior aspect and its multilamellar zoarium, this species 
may be confounded with Dakaria brevis. It differs from the latter in its aperture, 
of which the anter is rectilinear, in its hexagonal and much larger zooecia and in 
its ovicell imbedded in the distal zooecia. 
It differs from Hippoporella perforata in its smaller micrometric measure- 
ments and in its inferior face, where all the zooecia are not regularly perforated. 
O ccurrence.— Middle Jacksonian (Castle Hayne limestone) : Wilmington, 
North Carolina (common). 
Cotypes . — Cat. No. 64075, U.S.N.M. 
HIPPOPORELLA PERFORATA, new species. 
Plate 86. figs. 7-13. 
Description.- — The zoarium creeps on algae forming orbicular lamellae, free 
and irregular. The zooecia are hexagonal, very little elongated, distinct, sep- 
arated by a furrow ; the frontal is smooth and convex ; it is an olocyst perforated 
laterally by some large areolae. The aperture is semilunar, transverse; two deep 
cardelles separate a large anter from a small rectilinear poster. The ovicell is 
very large, imbedded in the distal zooecium and is hyperstomial. It opens above the 
aperture by a large opening without connection with the operculum. On the lower 
face of the zoarium the zooecia are convex, hexagonal, perforated in front of the 
aperture by a round pore, and striated transversely. The ancestrula is membrani- 
poroid. 
