ABT. 21 CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER 71 



of the tubes with facettes are terminal, orbicular, with a peristome 

 thin and little salient; the facettes are elongated, hexagonal, little 

 distinct. 



Measurements. — Diameter of peristomes, 0.14-0.16 mm.; diameter 

 of orbicular orifices, 0.10 mm.; diameter of lozenge-shaped orifices, 

 0.06-0.08 mm.; diameter of branches, 1 mm. 



Affinities. — This new species differs from Ceriocava multilamellosa 

 in its smaller branches, in the lozenge-shaped tubes without facettes, 

 and in the terminal position of the orifices on the facettes. 



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

 Switzerland (common) . 



Coty'pes.—Qs.i. No. 69924, U.S.N.M. 



DIPLOCAVA, new genus 



Ceriocavidae with dimorphic zooccia. 



Genotype. — Diplocava incondita, new species. Lower Cretaceous 

 (Neocomian). In this genus tubes without facettes and much larger 

 dimensions appear. They are most frequently in more or less orbic- 

 ular and salient groups; rarely they are scattered. They are not 

 constant, and it is not rare to discover zoarial fragments which lack 

 them. The determination of species of this genus is therefore very 

 difficult, especially on isolated specimens. The ovicell has not yet 

 been discovered. 



DIPLOCAVA INCONDITA, new species 



Plate 10, figs. 5-12 



Description. — The zoarium is free, dichotomous, in unilamellar 

 fronds or in irregularly cylindrical, multilamellar fragments. The 

 large zooecia are always open, grouped in salient orbicular areas 

 which are separated from each other by zones of small zooecia with 

 facettes. The facettes are hexagonal, distinct, separated by a 

 furrow, convex, smooth, perforated in the middle. The apertura is 

 large, orbicular, surrounded by a thin and salient peristome. The 

 ovicell is star-shaped, with four branches, placed in the midst of the 

 large tubes. 



Measurements. — Diameter of aperture, 0.14 mm. ; diameter of peri- 

 stome, 0.20 mm.; diameter of facettes, 0.30 mm.; diameter of exter- 

 nal orifice of large tubes, 0.30 mm.; diameter of external orifice of 

 small tubes, 0.20 mm.; diameter of the large branches, 5 mm. 



Variations. — This species is very irregular in its external aspect. 

 We have observed some lamellar fragments simple or double with 

 monomorphic zooecia, arborescent fragments formed of small tubes 

 only, fragments formed of tubes with facettes only, irregular frag- 

 ments formed of an inner trunk of zooecia with facettes, covered 



