562 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Genotypes. — Adeonella polymorpha Busk, 1884, and Adeonella (. Eschara ) 
polystomella Reuss, 1847. 
Range. — Jacksonian — Recent. 
ADEONELLA FOLLICULATA Canu and Bassler, 1917. 
Plate 72, figs. 1-8. 
1917. Adeonella folliculata Canit and Bassler, Synopsis of American Early Tertiary Cheilo- 
stome Bryozoa, Bulletin 90. United States National Museum, p. 66, pi. 6, fig. 3. 
Description.- — The zoarium bilamellar with two lamellae, back to back, and sep- 
arable. The fronds are lobed, very thin , and fragile. The zooecia are very long, 
distinct, separated by a furrow, little convex, bordered with numerous parietal 
areolae (10-12 pairs). The peristomie is short, somewhat projecting exteriorly 
and is perforated by a spiramen ; the peristomice is semilunar with a convex lower 
lip; the aperture (interior) presents a proximal concave border. The gonoecia 
are (0.30 mm.) larger than the other zooecia; their external aperture is greater 
(?a=0.10 mm.) and the spiramen is more removed from the aperture. There is a 
very small, simple avicularium on the peristome. 
, . \L, 3 = 0.65-0.75 mm. ... . fZs=0.50mm. 
Measurements.- — Lateral zooecia-]. n nA n Axial zooecia]. n nA 
1/3=0.20—0.25 mm. 1/3=0.20 mm. 
Gonoecia J ^ 3== 0.50 mm. Peristomice of fA^=0.04mm. 
l7.?=0.30mm. zooecia l lp= 0.07 mm. 
Peristomice of (A;?=0.04 mm. 
gonoscia \lp=0.10 mm. 
Variations. — The zooecial walls are so thin and fragile that it is difficult to 
obtain a good interior presenting all the characters of the species, and it is neces- 
sary to study this feature by successive rubbing away of the substance. 
The axial zooecia are shorter than the lateral ones (figs. 3, 6), nevertheless there 
are fronds composed uniquely of long zooecia alone (fig. 4). 
Often one of the parietal areolae is transformed into a small, simple avicu- 
larium, slightly pointed (fig. 2) and of inconstant position. Just as the zooecial 
areolae may be transformed into avicularia, the parietal pores resulting from a 
growth of the ectocvst are susceptible to continuation of evolution, according to 
the needs of the zoarium. 
The small peristomial avicularium is round; its place is very variable, but 
always on the distal border. 
The gonoecia are somewhat larger (0.30 mm.) and their external aperture also 
larger (0.10 mm.) ; the spiramen is placed farther from the external aperture and 
perhaps it opened exactly at the level of the operculum, instead of being above it 
(fig. 6). 
Figure 5 represents a very common alteration by fossilization. 
The fronds have the thinness of a leaf and are very fragile. 
Occurrence. — -Middle Jacksonian (Castle Hay ne limestone) : Wilmington. North 
Carolina ( common ) . 
Cotypes.- — Cat. No. 62608, U.S.N.M. 
