30 PKOCEEDINGS OF THE NATIONAL MUSEUM. vol.61. 



NOTOPLAGIOECIA FARRINGDONENSIS, new species. 



Plate 1, fig. 18. 



Description. — The zoarium is free, cylindrical or compressed. The 

 tubes are indistinct, very little convex, smooth. The peristomes are 

 orbicular, thin, arranged in quincunx or in transverse rows. The 

 zone of growth is an elevated cone. The ovicell is an irregular sack 

 covering many adjacent tubes. 



Diameter of aperture 0. IG mm. 



Diameter of peristome .20 mm. 



Measurements.— \ Distance of peristome .48-0.56 mm. 



Separation of peristomes .72 mm. 



Diameter of branches 3.00 mm. 



Structure. — In longitudinal sections the tubes are short, club 

 shaped, much expanded at their terminal parts, sometimes showing 

 pseudofacettes. The gemmation is dorsal, although triparietal in 

 appearance because of the little length of the tubes. The walls are 

 moniliform, much widened at their extremity. 



In transverse sections the tubes are rounded, much smaller at the 

 center than at the circumference, with very thick vesicular walls, 

 especially at the periphery. 



Occurrence. — Lower Cretaceous (Aptian) : Farringdon, England. 



Cotypes.—Q^t. No. 68718, U.S.N.M. 



NOTOPLAGIOECIA MAGNIPORA, new species. 



Plate 5, figs. 3, 4. 



Description. — The zoarium is free, cylindrical, bifurcated {Enta- 

 lophora form of growth). The tubes are indistinct, large, open in 

 quincunx, not raised at their extremity; the peristome is very thin 

 and scarcely salient. The ovicell is enormous, very convex, covering 

 half of the zoarium ; the oeciostome is much smaller than a zooecium, 

 somewhat salient and placed at the distal extremity. 



Diameter of peristome 0.25-0.30 mm. 



Distance of orifices .83- .85 mm. 



Separation of orifices .83- ,85 mm. 



Diameter of branches 2. 10 mm. 



A-fjinities. — In the size of the peristomes, this species can only be 

 compared to Entalophora grandipora Vine, 1885, of the English 

 Coniacian, but it diiffers in its nonvisible tubes and in its lesser dis- 

 tance between the orifices. 



In species of Plagioecia we rarely find the oeciostome because it is 

 very small and is confused with the secondary perforations of the 

 surface. Here, however, it is quite visible, although remaining very 

 small in comparison with the tubes. 



Measurements.— > 



