NORTH AMERICAN EARLY TERTIARY BRYOZOA. 33 



HIPPOMENELLA ANGUSTAEDES, new species. 



Plate 49, figs. 18, 19. 



Description. The zoarium is free and formed of two lamellae, back to back, 

 and inseparable; the fronds are of little width, flabellate, and do not contain more 

 than six longitudinal rows of zooecia. The zooecia are elongated, distinct, oval; 

 the frontal is convex, smooth, and garnished with a double lateral row of areolae, 

 numerous and small. The aperture is elliptical, elongated, divided into equal parts 

 by two cardelles; the peristome very little salient, bears 4 to 6 large distal spines. 

 The avicularia are placed laterally in the vicinity of and below the aperture ; they 

 have a pivot and their triangular beak is directed downward ; they are never equal 

 in size. 



,, ffl<z=0.16mm. . 1 7.2=0.70-0.80 mm. 



Measurements. Aperture i 7 ..,. ZooeciaX ., 



I /0=0.12 mm. 1 7?=0.46 mm. 



Affinities. This species differs from Hippomenella transversata in its smaller 

 micrometric measurements (Zs<0.80 mm.) and in its lower placed avicularia. 

 which are larger and more oblique. 



It differs from Hippomenella incondita in its much smaller avicularia and 

 its orifice exteriorly elliptical and not semilunar. 



It differs from Hippo?nenella capitimortis in the size of its avicularia and in 

 its aperture exteriorly elliptical (and not semilunar). 



It differs from Hippomenella costiilata in its avicularia placed lower and 

 with a beak turned downward (and not laterally) and in the presence of oral spines. 



It differs from Hippomcnclla rotula in its narrow fronds and its elliptical 

 aperture garnished with spines. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, 

 North Carolina (rare). 



Holotype.C&i. No. 64079, U.S.N.M. 



HIPPOMENELLA INCONDITA, new species. 



Plate 50, figs 1-8. 



Description. The zoarium is free, formed of two lamellae, back to back, and 

 inseparable; the fronds are wide, irregular, and undulated. The zooecia are dis- 

 tinct, somewhat elongated, elliptical, swollen; the frontal is convex and garnished 

 laterally with a double row of large areolae. The aperture is exteriorly semi- 

 lunar; the proximal border has a very convex mucronoid protuberance. The ovicell 

 is hyperstomial, salient, globular, much imbedded in the distal zooecia, never closed 

 by the operculum, very irregularly punctate. The avicularia are placed laterally 

 on the line of the areolae. close to and somewhat below the aperture; they are 

 small, little prominent, and their beak is directed downward. No spines. 



Measurements. Aperture I a=0.13 mm. . |Zs=0.75-0.90mm. 



(exterior) |?a=0.15 mm. 173=0.24-0.25 mm. 



Variations. The zooecia are long (fig. 2) or short (fig. 3). The punctations 

 of the ovicell are very irregular (figs. 5-7) and rarely (fig. 6) it is possible to 



