ART. 21 CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER 75 



the small tubes is quite considerable. According to these two latter 

 observations, it might be concluded that the dimorphism observed in 

 Diplocava is more apparent than real and that it occurs only at the 

 terminal part of the tubes. 



Affinities. — This species differs from Diplocava incondita in its non- 

 arborescent zoarium, its smaller micromctric dimensions, and in its 

 less apparent dimorphism. 



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

 Switzerland (very rare). 



Coti/2)e. —Cat. No. 69928, U.S.N.M. 



Cenus SPIROCLAUSA D'Orbigny, 1852 



SPIROCLAUSA NEOCOMIENSIS De Loriol, 1863 



Plate 11, fig. 14 



1863. Spiroclausa neocomiensis De Loriol, Les Invert6br6s du Neocomien in- 

 f^rieur du Mont Saleve pres Geneve, p. 137, pi. 17, fig. 5. 



Our figured specimen does not much resemble that of De Loriol, 

 but not being able to make sections, we do not believe we ought to 

 create a new species for it. 



Its relationships seem to us to be with the Diplocava, for the supe- 

 rior tubes of the spires are much larger than the others. In each 

 spire there is always one or more circles of inclosed zooecia. 



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

 Switzerland. 



Plesiotype.—Cait. No. 69929, U.S.N.M. 



Family LEIOSOECIIDAE Canu and Bassler, 1920 

 Genus LEIOSOECIA Canu and Bassler, 1920 



LEIOSOECIA AEQUIPOROSA, new species 



Plate 16, figs. 15-18 



Description. — The zoarium is free, cylindrical. The orifices are 

 suborbicular and slightly polygonal ; the peristomes are thick, non- 

 salient, arranged in quincunx. The mesopores are little numerous, 

 irregular, polygonal, equal to the apertures. The ovicell is large, 

 orbicular or somewhat elliptical, thin, very convex. 



Measurements. — Diameter of orifices, 0.10 mm.; diameter of meso- 

 pores, 0.08-0.10 mm.; diameter of zoarium, 2.5 mm. 



Structure. — In longitudinal section the tubes are cylindrical. The 

 mesopores are rare, rather long, with thickened, hollow or moniliform 

 walls. 



