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BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 
Fig. 3.—Genus Chaperia Jullien, 1881. 
Figs. A-G. Chaperia acanthina Quoy and Gaymard, 1824. 
A. Interior of a zooecium showing the polypide and the retractor muscles of the operculum. These 
are the two enormous muscular bundles which characterize the family Chaperiidae, determining in 
the zooecia the formation of the calcareous lateral plates situated below the orifice. Such plates are the 
most characteristic remains of this anatomical arrangement which existed as far back as the Creta¬ 
ceous period. 
B. A young colony, X 70, treated with ‘‘eau de javelle,” showing the ancestrula with the base of 
the spine of the circumference. In this ancestrula the two lateral funnels which serve for the insertion 
of the retractor muscles of the operculum, can be seen. 
C. Diatoms and radiolaria found in the digestive apparatus of this species, X 216. The radiolarian 
is Dyctioca speculum Ehrenberg, a species encountered in many other brvozoa. 
D. Very young zooecium bearing spines and in the orifice of which the funnels in process of forma¬ 
tion, still unseparated, can be seen. 
E. Zooecia covered over by the ectocyst and bearing marginal spines. (Figs. A-E, after Jullien, 
1888.) 
F. Operculum (after Kirkpatrick, 1890). 
