46 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.61. 



The anangenient of the tubes is as in Perlpora and this is the 

 first time that we have discovered an ovicelled specimen. 



Gregory, in 1899, gives a long synonymy of this species. This 

 appears premature to us and we can maintain it only when we 

 have discovered in France ovicelled specimens of the different spe- 

 cies of Perlpora described by D'Orbigny. 



Occurrence. — Cretaceous (Danian) :Herfolge (Seeland), Denmark. 

 Also in the Maastrichtian at Maastricht, Holland. 



PJesiotype.—CM. No. 68927, U.S.N.M. 



DIAPER0ECIA7 AMERICANA Gabb and Horn, 1862. 



Plate 9, figs. 6-10. 



18G2. Fascipora anicricana Gabb and Horn, Journal Academy of Natural 

 Sciences, Philadelphia, ser. 2, vol. 5, p. 165, pi. 21, fig. 54. 



Description. — The zoarium is free, cylindrical, in the Entalophora 

 form with the branches clavate, short, and bifurcated. The tubes 

 are little distinct, very little convex, sometimes bordered; the peri 

 stome is thin, little salient, orbicuhir. The ovicell is large, ellip- 

 tical, transverse, globular, salient, perforated by the widely sepa- 

 rated tubes. The zone of growth is terminal and very thick. 



Diameter of peristome 0.14-0.16 mm. 



Distance between peristomes 0.50 mm. 



Measurements. — \ Separation of peristomes 0.50 mm. 



Smallest diameter of branches. 1.4 mm. 



(xreatest diameter of branches. 2.00 mm. 



Affinities. — This species is quite well characterized by the clavate 

 form of its branches; the upper part is wider and often is occupied 

 by the ovicell. The tubes are sometimes fiat and bordered with a 

 very salient thread: generally they are little distinct. We have 

 figured a branch in Avhich the lower tubes are not pointed in the 

 same direction as the upper tubes. We are unable to explain tb.is 

 curious growth. 



At the base of the branches the length of the tubes varies from 

 0.90 to 1.00 mm. The ovicell is often almost analogous with Plxu/l- 

 oecia. In realitj this seems to be an intermediate type between 

 Plugioecia and Diaperoecia. The discovery of the oeciostome will 

 permit an exact generic classification. 



Occurrence. — Cretaceous (Vincentown iiiarl) : "^'incentown. New 

 Jersey. 



PUsiotypes.—i^2i\. No. G8928. U.S.N.M. 



Genus DIPLOSOLEN Canu, 1918. 



This genus is like Diaperoecia save that adventitious tubules 

 (zooeciules) are developed. 



Genotype. — Diplosolen {Berenicea) ohelium Johnston, 1847. 

 Rarige. — Cretaceous — Eecent. 



