152 
BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 
Genus CYSTISELLA Canu and Bassler, 1917. 
(For description, see Bulletin 106, U. S. National Museum, p. 479.) 
. CYSTISELLA AVICULIFERA, new species. 
Plate 38, fig. 8. 
Description. —The zoarium incrusts pebbles or algae. The zooecia are distinct, 
elongate, subelliptical, swollen: the frontal is convex, smooth or bears an avicularian 
chamber rather large and somewhat salient. The apertura is semicircular and 
placed at the base of a deep peristomie; the peristome is thin, salient, and bears 
two or three orbicular avicularia. The ovicell is large, hyperstomial, convex, 
globular, smooth; it opens into the peristomie by a very large opening placed 
above the operculum. 
,, J -p. . , \hve = 0.15-0.18 mm. „ . [Z 2 = 0.65 mm. 
Measurements. —renstomice 7 _ ,. Zooecia , „ 
[lpe = 0.16 mm. I Zz = 0.40 mm. 
Affinities. —Our micrometric measurements are taken on the marginal zooecia; 
at the center of the zoarium they are much smaller, the frontal of the zooecia 
being much reduced there. The ancestrular zooecia appear to be erect as in the 
Celleporidae; this aspect is deceiving and is occasioned by the presence of small 
peristomial avicularia; they are perfectly oriented like the marginal zooecia but 
much smaller. The relative constancy of the peristomice permits us to utilize the 
micrometric measurements. The frontal avicularian chamber is much smaller than 
in the other species of the same genus; but the absence of the areolar pores leaves 
no doubt as to the exactness of our generic determination. The multiplicity of 
avicularia on a given species always reveals whether the water was calm or not 
very agitated. 
Occurrence. —Pleistocene: Santa Barbara (rare) and Santa Monica, California 
(rare). 
Holotype. —Cat. No. 68659, U.S.N.M. 
Family RETEPORIDAE Smitt, 1867. 
Genus RETEPORA Imperato, 1599. 
(For description, see Bulletin 106, U. S. National Museum, p. 500.) 
RETEPORA DOVERENSIS Ulrich and Bassler, 1904. 
Plate 23, figs. 11-17. 
1904. Retepora doveremis Ulrich and Bassler, Maryland Geological Survey, Miocene, p. 422, 
pi. Ill, figs. 5-7; pi. 115, figs. 1-5. 
The original description follows: 
Zoarium reticulate, fenestrae of variable size, averaging 0.8 mm. long and about 0.4 mm. wide. 
Branches varying from 0.2 mm. to 1.0 mm. wide, usually about 0.6 mm.; reverse solid, the surface 
generally smooth, occasionally minutely granulose, divided into irregular angular spaces by fine 
impressed or raised lines that may or may not correspond with the bases of the zooecial walls. Zooecia 
immersed, with oblique imbricating and slightly flaring mouths, and a narrow notch in the elevated 
and angular proximal border. The appearance of the celluliferous surface varies greatly in different 
specimens, the difference being due chiefly to the presence or absence and number of the avicularia 
and ovicells. The latter appear as bulbous inflations with a slit running from the center to one edge. 
When they occur at all it is usually in abundance. Of avicularia there are at least two sets, the larger 
ones occurring on the front of the zooecia, forming its highest part and causing it to appear inflated. 
