ART. 21 CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER 79 



LEIOSOECIA PROXIMA. new species 



Plate 17, figs. 12-15 



Description. — The zoarium is free, siibcylindrical, bifurcated. The 

 orifices are orbicular or subpolygonal, with sahent peristomes. The 

 mesopores are polygonal, smaller than the apertures, few in number. 

 The ovicells are orbicular, very convex, smooth. 



Measurements. — Diameter of aperture, 0.10-0.12 mm.; diameter 

 of mesopores, 0.08 mm. ; diameter of zoarium, 4 mm. 



Affinities. — In its exterior aspect this species is very close to Leio- 

 soecia constanti D'Orbigny, 1854. We believe, however, they are dis- 

 tinct. The zoarium is, in fact, multilamellar, as the longitudinal and 

 transverse sections prove. There are no epithecal lines. Finally, in 

 spite of irregularity of the specimens, the gemmation is peripheral 

 but more axial and the central bundle of tubes is smaller. 



Our longitudinal section is very interesting, as it shows the begin- 

 ning of the exterior lamella. This is a tube which is prolonged on 

 the surface of the primitive trunk which in turn is covered by the 

 proliferation of its successive ramifications by dorsal gemmation. 

 The phenomenon is then absolutely identical with that of lamellate 

 Re-ptomulticrescis forms. It is thus proved that in such zoarial forms 

 as Heteropora, Reptomulticrescis, and Reptomulticava there are two 

 kinds of gemmation, dorsal and peripheral. 



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

 zerland (rare). 



Cotypes.—Qa.t. No. 69931, U.S.N.M. 



Family CLAUSIDAE D'Orbigny, 1854 



Genus CLAUSA D'Orbigny, 1854 



CLAUSA CRANEI, new species 



Plate 17, figs. 6, 7 



Description. — The zoarium is free, claviform. The peristomes are 

 thin, nonsalient, arranged in interrupted transverse lines, and sepa- 

 rated by small numerous, polygonal dactyletlirae. 



Measurements. — Diameter of orifice, 0.08 mm.; diameter of peri- 

 stome, 0.10 mm.; diameter of zoarium, 1 mm. 



Affinities. — Only the type specimen has been found, and we have 

 figured it not only because of its perfect preservation but in order 

 to show that the genus Clausa appears to be well represented in the 

 Lower Cretaceous, where it has hitherto never been noted. 



The species differs from Clausa zonifera, new species, in its peri- 

 stomes not grouped in zones and in its smaller orifices. The specific 

 name is in honor of W. E. Crane, who collected the fine bryozoan 

 fauna here described from Faringdon. 

 53648—26 6 



