PEAT Bex ex: 
SEMAOSTOMITES ZITTELI (p. 70). 
Natural size, from a photograph. (After Haeckel.) 
a. Gastral cavity. 
b,-b,. The 4 oral arms. 
c,-¢,. The 3-sided pyramidal adradial papillze between the external corners of the gastral pouches 
and the genital pouches. 
dd, The 4 gastral pouches. 
f. The thickened mound-like ring which defines the peripheral boundary of the gastral pouches 
and the genital pouches. 
e, The smooth zone. 
g,-9,. The 4 genital pouches. 
h. The ring canal. 
i. The marginal lobes. 
k. Radial canals (k, perradial canals; k, interradial canals; k, adradial canals). 
1. Marginal tentacles. 
m. Periphery of the zone of rays formed by the marginal tentacles. 
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