NORTH AMERICAN EARLY TERTIARY BRYOZOA. 747 



DIPLOSOLEN PLANUM. new species. 



Plate 122, figs. 14-16. 



Description. The zoarium is free and bilamellar. The tubes are little dis- 

 tinct, flat, oval, arranged in irregular quincunx, much scattered; the peristome is 

 elliptical, thin, horizontal, often closed by a porous calcareous lamella. The 

 adventitous tubules are indistinct, terminated by an elliptical aperture, arranged 

 above each tubular peristome. The ovicell is convex, suborbicular, spread over 

 a dozen tubes. 



Diameter of the peristome 0.08-0.10 mm. 



Diameter of the tubes 0.140.16 mm. 



Distance between the peristomes ... 0.70-0.80 mm. 



Separation of the peristomes 0.50-0.55 mm. 



Affinities. This species resembles Diplosolen obclium Johnston, 1847; it dif- 

 fers from it in its flat tubes, bilamellar zoarium, and scarcely visible zooeciules. 

 Occurrence. Middle Jacksonian: Near Lenuds Ferry, South Carolina (rare). 

 Holotj/pc.C&t. No. 65430, U.S.N.M. 



LEKYTHIONIA, new genus. 



Greek: Lefcytfyion, small flask; in allusion to the form of the oeciostome. 

 The ovicell is not perforated by the adventitious tubules. The oeciostome is 

 isolated, oval, in the form of a bottle or flask. 



Genotype. LeJc>ythionia (Reticulipora) dichotoma Gabb and Horn, 1862. 

 Range. Upper Cretaceous, Lower Eocene. 



LEKYTHIONIA DICHOTOMA Gabb and Horn. 1862. 



Plate 104, figs. 7-13. 



1862. Rcticttlipnra dichotoma GABB and HORN, Monograph Fossil Polyzoa Secondary and 



Tertiary Formations of North America, Journal Academy Natural Science, 



Philadelphia, ser. 2, vol. 5, p. 173, pi. 21, fig. 64. 

 1901. Reticulipora dichotoma ULBICH, Maryland Geological Survey, Eocene, p. 207, pi. 59, 



figs. 9-12. 

 1907. ReticuUpora dichotoma WELLER, Cretaceous Faunas, Geological Survey New Jersey, 



Paleontology, vol. 4, p. 318, pi. 21, figs. 5-14. 



Description. The zoarium incrusts shells and stones; it emits bilamellar 

 expansions produced by a folding of the primitive lobes; these expansions, with the 

 large zone of growth develop very irregularly and anastomose in a very compli- 

 cated network. The tubes are indistinct, arranged in quincunx or in little con- 

 stant rows. The tubules are irregularly arranged on the zoarium. The ovicell 

 is orbicular or elliptical, not convex, spread among a dozen tubes, not perforated 

 (by the adventitious tubules; the oeciostome is isolated, oval, provided with an 

 oeciostome more or less large. 



Measurement. Maximum diameter of the peristome 0.12 mm. 



We have little to add to the excellent description given in 1901 by Ulrich, but 

 the progress of science permits us to understand the structure of the species better. 



