606 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
long, surrounded by areolae ; the oral mucro bears no avicularia. The deep zooecia 
are visible only by their apertura. The incomplete zooecia are rare. 
,, , . , fAa— 0.10-0.12 mm. 
M casurements. — Apertura { 7 _ . . . _ 
x 1^=0.10-0.12 mm. 
Variations. — This species is well characterized by its large, oral avicularium and 
by the fissure of its ovicell. The marginal zooecia exist only on the solid substratum 
(shells or bryozoa) (fig. 4). They evidently do not exist on the hollow tubular 
zoaria, which surround the radicells of algae. Likewise the incomplete zooecia 
exist only on the latter (fig. 5). In the interior the operculum articulates on two 
small condyles. 
Affinities. — This species much resembles Holoporella altirostris. It differs from 
it in its larger apertura and in the absence of pedunculate avicularia on the deep 
zooecia. 
It differs from Holoporella albirostris Smitt, 1872, of the waters of Florida, 
in the absence of the interzooecial avicularia, but it is very closely related. 
Occurrence. — Lower Jacksonian (Moodys marl) : Jackson, Mississippi (com- 
mon). 
Jacksonian (Zeuglodon zone) : Shubuta, Mississippi (rare). 
Vicksburgian (Marianna limestone) : West bank of Conecuh River, Escambia 
County, Alabama (rare) ; Murder Creek, east of Castlebury, Conecuh County, 
Alabama (rare). 
Cotypes.- — Cat. Nos. 64216, 64217, U.S.N.M. 
HOLOPORELLA ALTIROSTRIS, new species. 
O 
Plate 75, figs. 16-20. 
Description. — The zoarium forms small globular masses attached to other 
bryozoa, shells, or algae. The superficial zooecia are very salient, erect, irregular; 
the frontal is smooth and terminated by a prominent beak , bearing an enormous 
oral avicularium with pivot; the terminal portion of the beak is fringed and 
partially hides the apertura. The apertura is oblique, semilunar and formed of 
a large, finely crenulated anter, separated by two small cardelles placed very low 
from a concave poster ; the peristome, thin and little salient, bears two symmetrical 
spines. The ovicell is recumbent, hyperstomial, transverse, smooth, globular, 
widely open above the apertura and at the level of the large oral avicularium; 
it bears in front either a small, fragile, cicatrix or a fissure. The deep zooecia 
have no frontal ; their apertura is visible and the oral avicularium is quite salient 
and pedunculate. The incomplete zooecia are rare. 
. fAa=0.09mm. 
Measurements . — Apertura { , A , „ 
1 [te=0.10mm. 
Affinities. — In its zoarium and in its ovicell, sometimes fissured, this species 
much resembles Holoporella fissurata. It differs from it in its much larger oral 
avicularium becoming pedunculate on the deep zooecia. 
