CYCL.0ST0MATOUS BKYOZOA CANU AND BASSLER 



15 



Measurements. — Diameter of apertures, 0.04 mm.; diameter of 

 mesopores, 0.03 mm.; diameter of zoarium, 7 mm. 



Structure. — The meridian section shows cylinch-ical tubes with solid 

 thickened walls. The lamellae are formed by orbicular subcolonies 

 invisible externally. The epithecal lines are thin and rare. The 

 basal lamellae are thick. The mesopores are long and of little 

 diameter; they are only visible in the portions where the subcolonies 

 are cut in the same axis as their initial cell. 



Affinities. — This species differs from Multicrescis galaefera in its 

 still smaller micrometric measurements and its globular and smaller 

 zoarium. 



If till 



■ ij' 8 ^ ^ i! 



B 



mmm 



Fig. 3.— Genus Multicrescis D'Orbigny, 1852. A, B. MuUicrescislandrioti MicheWn, 1841. A. Portion 

 of a meridian seition, X 16, showing two superposed lamellae. B. Sketch, X 30, exhibiting annular 

 structureof the tubes. Lower Cretaceous (Valangian): Sainte-Croix, Switzerland. C. Multicrescis par- 

 vipora, new species. Meridian section, X 16. The tubes of the enveloping lamellae arc perpendicular 

 to the tubes of the primitive zoarium. Each lamella is formed of a variable number of subcolonies. 

 Lower Cretaceous (Valangian): Sainte-Croix, Switzerland 



It differs from Re/ptomulticava fungiformis, Gregory, 1009, from 

 Faringdon, England, in its much smaller zoarium and in the 

 presence of small visors on the tubes. 



Occurrence. — Lower Cretaceous (Valangian): Sainte-Croix (Vaud), 

 Switzerland (rare). 



Cotypes. — Cat. No. 69855, U.S.N.M., and Museum Comparative 

 Zoology. 



MULTICRESCIS (?) LANDRIOTI Michelin. 1841 



Plate 20, figs. 12-15 



1909. Semimulticavea landrioti Gregory, Catalogue of the Cretaceous Bryozoa 

 in the British Museum, vol. 2, p. 242, (Bibliography.) 



