NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 25 



The species mav perhaps be confused with Calhpora dumerilli Savigny-Au- 

 douin, 1826, in which the exterior aspect is quite similar; it differs from it m the 

 presence of nodules instead of avicularia placed on the gymnocyst (and not between 



the opesia). , „ , t ■ r \ 



Occurrence.— Lower Miocene (Bowden marl): Bowden, Jamaica (rare). 



Eabitat. — Florida (Hincks). 

 Plesiotypes.—C&t. No. 68410, U.S.N.M. 



MEMBRANIPORINA BACCAT.\, new species. 



Plate 9, fig. 14. 

 Descripiwn.—T\ie zoarium is mcrusting, unilamellar. The zooecia are distinct, 

 separated by a deep furrow, much elongated, elliptical or irregular^ The mural rim 

 is thm, regular, salient, rounded, covered with large granules. The opesium has 

 the same form as the zooecium. 



^ . f?io = 0.50mm. Zooecia "^^^^-''^ °'°'- 



Measurements.— O-pesm | ^^ _ q 22 mm. i^ooecia ^ ^^ _ ^ 35 ^^ 



Variations.— The zooecia giving rise to new series are much larger; they are 

 numerous, and when the zoarium is not perfectly regular the smaller zooecia which 

 they emit have not sufficient place for development and thus become deformed. 



We have noted traces of spicules, so that this species could possibly belong to 

 the genus AcantUdesia. However, it is imprudent to pronounce on this point 

 from a smgle specimen. The ensemble of the large granules of the mural rims give 

 to this species the aspect of a chain of pearls. , . „ ., . 



Occurrence.-mocene (St. Mary's formation): Bowler's wharf, IS mdes above 

 Urbana, Middlesex County, Virginia (rare). 



Holotype.— Cat. No. 68411, U.S.N.M. 



MEMBRANIPORINA CAUFORNICA Gabb and Horn. 1862. 



Plate 33, fig. 6. 



1862. Membranipora califomica Gabb and Horn, Monograph Polyzoa Secondary and Tertiary 

 formations of North America, Journal Academy Natural Sciences of Philadelphia, ser. ., 

 vol. 5, p. 160, pi. 20, fig. 46. 

 The original description is as follows: 



Colony encrusting, cellules arranged in lines, not always in regular quincunx. Cellules pyriform. 

 sometimes continued behind, often abruptly truncated. Opening large, occupying two-thirds or more 

 oUhe cellules; varying from rounded triangular to oval, usually narrowest in front, never sharply acumi- 

 na e Surfac; soSmes rounded about the oval opening, at other, carinate. nudway between the 

 aperture and the margin of the cellule, from which line the surface slopes downwards, con exMn 

 both directions. Behind the opening the surface is convex, often narrow. No abortive cellules nor 

 ovarian vescicles were observed. 



We have been unable to find specimens of this species and we therefore repro- 

 duce the original description and figures for the benefit of future students. 

 Occurrence.— Pleistocene: Santa Barbara, California. 

 12184— 23— Bull. 12.1 3 



