60 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.61. 



DIPLODESMOPORA OPPOSITA. new species. 



Plate 27, figs. 19-25. 

 Description. — ^The zoariiim is free, linear, with triangular section, 

 with bifurcated branches. The fascicles are salient, monoserial or 

 biserial, opposite, arranged on each side of the median crest. The 

 tubes are visible; the peristomes are thin and quadrangular. The 

 ovicell is quite large, elliptical, elongated, placed laterally in the 

 vicinity of the fascicles, smooth and globular. 



I Diameter of peristomes 0.08 mm. 

 Separation of fascicles .40 mm. 

 Diameter of branches 1.33 mm. 



Validations. — The fascicles are often monoserial and the branches 

 have absolutel}' the aspect of Idmonea, but more often the fascicles 

 are biserial and formed of a dozen tubes. 



The ovicell is v^ery regular, margined by a sort of collar ; it does not 

 grow from a tube of a fascicle, but from a more lateral tube and is 

 placed between two fascicles. 



A thin epitheca covers the nematopores; the dorsal then appears 

 smooth. At the least weathering the nematopores appear in their 

 usual occurrence from below upward. 



In transverse section the tubes are smaller in the vicinity of the 

 dorsal and correspond to the funnel-shaped tubes. The dorsal is 

 very thick and perforated by pores corresponding to the nemato- 

 pores. The section is more or less triangular, according to the place 

 where it is made. 



The longitudinal section is quite regular. The tubes are long, 

 funnel shaped with dorsal gemmation. They are ramified in long, 

 rectilinear dorsal nematopores with very thick walls. 



Occurrence. — Cretaceous (Coniacian) : Tours and Ste. Paterne 

 (Indre-et-Loire), France. 



Cotypes.—Camx collection and Cat. No. 68983, U.S.N.M. 



DIPLODESMOPORA ALTERNATA, new species. 



Plate 27, figs. 12-18. 



Descriptio7i. — Thezoarium is idmoneiform, f ree with a subtriangu- 

 lar section. The linear bundles are salient, uniserial, formed of 3 

 or 4 tubes and disposed alternately on each side of the median crest 

 The tubes are visible, little convex ; the peristome is thin. The ovi- 

 cell is very convex, slightly elongated, smooth, placed on the side of 

 the zoarium. The noncellular face is smooth and the nematopores 

 are closed by a very thin pellicle. 



Diameter of fascicles 0.18 mm. 



,r ^ , Distance of fascicles .25-0.30 mm. 



Measurements. — { tn- . ^ • ^ 



1 Diameter of peristome . 13 mm. 



1 Width of zoarium 1.00 mm. 



