268 MOLLUSCOIDEA—BRYOZOA SUB-KINGDOM V 
or less oblique, hooded, commonly of oval shape. Mesopores abundant, often com- 
pletely isolating the zowcia. Apertures closed by a thin calcareous sheet at maturity. 
Abundant in Ordovician. C. distincta, Ulrich. 
Crepipora, Ulrich (Fig. 436). Encrusting, lamellate, or massive, in one case forming 
hollow branches. Zocecial tubes long, partitioned off by a moderate number of 
diaphragms. Mesopores almost entirely restricted to the maculae, which are distributed 
over the surface as minutely porous elevations or depres- 
sions. Apertures very slightly oblique, angular, or 
sub-pyriform. Lunarium well-defined in perfect speci- 
mens, best shown in tangential sections. Ordovician, 
? Silurian. 

Fic. 438. 
Fic. 437. Ceramophylla frondosa, Ulr. Black 
Anolotichia impolita, Ulr. Lower Trenton; Minnesota. A, Surface, River Shales; Minnesota. <A, Zoar- 
6/;. B, Vertical section, 6/;. C, Tangential section, 12/;, showing tubes ium, 2/3 8B, Surface of same, 6/3. 
of Iunarium. D, Tangential section of A. ponderosa, Ulr., from the C, Two zoccia of a tangential 
Cincinnati formation at Wilmington, Ill., showing numerous lunarial section, 1%/;. D, Right half of a 
tubes (after Ulrich). vertical section, 12/; (after Ulrich). 
Anolotichia, Ulrich (Fig. 437). Zoaria large, ramose, or digitate, consisting of 
long, sub-polygonal tubes intersected by remote diaphragms. Mesopores never very 
numerous. Lunarium slightly elevated at the surface, traversed internally by two to 
six minute, vertical, closely tabulated tubes, Ordovician. 
Diamesopora, Hall (Coeloclema, Ulrich). Hollow branches, lined internally with a 

C 
~ 
Fic. 439. 
Diamesopora 
trentonensis, Ulr. 
Trenton ; Minne- = 
sota. Two frag- Fic, 440. 
ments, 2/3, and Bythotrypa lavata, Ulr. Trenton; Minnesota. A, Surface, 14/). B, Vertical 
one 8/). section, 7/;. C, Transverse section, 14/; (after Ulrich). 
striated epitheca. Zocwcia as in Ceramoporella, but with thicker walls. Ordovician 
and Silurian. 
Ceramophylla and Chiloporella, Ulrich. Ordovician. 
Bythotrypa, Ulrich (Fig. 440). Zoaria massive or lamellate, Zocecial tubes long, 
intersected by thin diaphragms. Lunarium large ; mesopores numerous, open at the 
surface, forming interiorly a very loose vesicular tissue. Ordovician. 
Scenellopora, Ulrich. Zoaria simple, pedunculate ; under surface with an epitheca, 
