PLATE XIII. 
Mist. (pIOTEYPA PARASITICA, n. sp. A tangential section. «18, . co WLS 
la. Surface of a specimen enlarged 18 diameters. 
1b. Vertical section, showing the division of the zoarium into numerous 
layers. < 18. 
1c. Portion of fig. 1, mignified 50 diameters, showing the perforated 
opercula or diaphragms, and spiniform tubuli in the thin zoecial 
walls. 
Fig. 2. TREMATOPORA TUBERCULOSA, Hall, Surface of a finely preserved, 
= “mature specimen.  X 18,_. ; : ; ai aes : : on hao 
Da Tangential section. X 18. 
2b. Longitudinal section. & 18. 
Fig. 3. TREMATOPORA HALLI, nu. sp. A branching fragment of this species. 
Natural size, : : ; g ; : : : i ioe 2k 
3a. Surface of same, enlarged 18 times. 
Fig. 4. TREMATOPORA WHITFIELDI,n.sp. Afragmentofthisspecies. Natural 
size, 5 5 : : Bf : : : : : a : 262 
4a Surface of same eels ved 18 times. 
Fig. 5. ANISOTRYPA SYMMETRICA, n. sp. A branch of this species, showing 
the distribution of the owcia(?). Below is given a sectional view 
of the lower end. Natural size, : : : s 05 
5a. Surface of athick-walled specimen, magnified 18 ddinnenens showing the 
true zocecial apertures at the bottom of the vestibules, and an (?) 
ocecium at the lower right hand corner. 
5b. A tangential section. 18. 
5c. A vertical section, representing, however, only one side of the branch. 
. 18. The specimen consisted of two layers of cells, growing in 
opposite directions. 
Fig. 6. HELIOTRYPA BIFOLIA, n. sp. Surface of a fine specimen, enlarged 
18 times, showing a maculum of interstitial cells at the lower left 
hand corner, : - : : 
6a. A tangential section enlarged 50 diameters. 
6b. A longitudinal section. > 18. 
6c. Portion of 6), magnified to 50 diameters. 
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