4a. 
. A lobate specimen, showing the base of two branches or spurs. Natural 
7G. 
8a 
PLATE XII. 
. ATACTOPORA HIRSUTA, Ulrich. A tangential section showing por- 
tion of a “macula.” << 18, A : ; 
. Longitudinal section, showing the entire thickness of alayer. 18. 
. 2. ATACTOPORA MACULATA, Ulrich. A tangential section, showing a 
= maciilay lls: 
. Longitudinal section, cut from a specimen consisting of three distinct 
layers of cells. The figure shows the middle one almost entire, 
and a portion of the upperlayer. 18. 
ATACTOPORELLA TYPICALIS, n. sp. The surface of an inerusting 
specimen, enlarged to 18 diameters, 
. A tangential section. 18. 
. A portion of 3a, enlarged to 50 diameters. 
. A longitudinal section, cut from a sub-ramose specimen. \ 18. 
. An aberrant example of this species, which has assumed a sub-fron- 
descent form. Natural size. 
. ATACTOPORELLA NEWPORTENSIS, n. sp. A ramose example of this 
species. Natural size, 
A tangential section. 35. 
size. 
3. ATACTOPORELLA SCHUCHERTI, n. sp. The surface of a specimen of 
this ‘species magnified 18 times, 
. A tangential section. > 18. 
. Part of 5a, magnified 50 times. 
. ATACTOPORELLA MUNDULA, Ulrich. A tangential section. X 18, 
. A vertical section. 18. 
. ATACTOPORELLA ORTONI, Nicholson. A tangential section, showing 
the filled interstitial cells of a monticule. 35, A : 
A vertical section of a specimen consisting of two layers of cells. On 
the left a portion of a monticule is represented. 35. 
ATACTOPORELLA MULTIGRANOSA, Ulrich. A vertical section. 18, 
. A tangential section. < 36. 
248 
250 
251 
252 
256 
254 
