NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
455 
Fig. 130. — Anatomy of the Smittinidae Levinsen, 1909. 
A, B. Porella levis Fleming, 1828. A. Free larva, X 75. B. Ancestrula. (A, B after 
Barrois, 1877.) 
ca, calotte (terminal bud) ; ph, pharynx; 
CD, digestive cavity ; si, furrow ; 
ce, portion of the body between the two g, disseminated fat globules seen in the stages 
branches of the stomach; following fixation; 
est, stomach ; pvl, rudiment of the polypide ; 
mi, aboral mesoderm ; sp, spines of cell. 
ms, oral mesoderm; 
C-E. Mucronella peachi Johnston, 1848. C, D. Ciliated embryoes. E. Zooecial anatomy. 
The place of the rectum does not appear to be exact. Letters as in figure G. (C-E after 
Smitt, 1865. ) ' 
F, G. Porella cervicornis Pallas, 1766. F. Polypide with the tentacles arranged in the 
tentacular sheath. G. The same with the tentacles extended. (F, G after Milne-Edwards, 
1838. ) 
bg, edge of the tentacular sheath ; 
coec, caecum of the stomach ; 
est, stomach ; 
mr, retractor muscles of the polypide ; 
/, filiform appendages of alimentary canal ; 
ph, pharynx ; 
r, rectum ; 
t, tentacles. 
H. Smittina trispinosa Johnston, 183S, var. arborea Levinsen, 1886. The compensatrix (cs) 
is attached to the operculum (op). Its orifice is overhung by a median lobe of the frontal 
shield. The condyles (cond) are at a much deeper level and are long recurved denticles, which 
are crossed by the submarginal lateral sclerites ( set ) of the operculum. The author has not 
figured the parietal muscles. (After Harmer, 1902.) 
I. Smittina tripora Waters, 1904. Section showing aperture with operculum, and below it 
the avicularian glands, with the mandible above the glands, X 85. (After Waters, 1904.) 
J. Smittina protecta Thornely, 1907. Polypide removed from the zooeeium, showing the 
small oral (vaginal of Calvet) glands (g), the diaphragm ( d ), and the tentacles (<), X 85. 
(After Waters, 1908.) 
K. Smittina ophidiana Waters, 1878. Distal extremity showing the oral glands, X 85. 
(After Waters, 1892.) 
L. 'Smittina trispinosa Johnston, 1838. Distal end, showing oral glands, X 85. (After 
Waters, 1S92.) 
M, N. Porella acutirostris Smitt, 1867. M. Piece mounted in balsam, showing the avion 
larian glands through the semitransparent shell, X 50. N. Section of avicularian gland, X 
250. (M, N after Waters, 1900.) 
O. Sketch of several zooecia, showing terminology. 
