4^ BULLETIN m, UNITED STATES NATIONAL MUSEUM. 



laterally two areas in the form of a lunar crescent and more or less 

 perforated. There are nearly always some spines and some avicularia. 



Genotype. — Hipyortienella {Lepralia) mucronelliformis Waters, 

 1899. 



Range. — Lutecian-Eecent. 



HIPPOZEUGOSELLA, new genus. 



{Ilippos^ horse, in reference to the horseshoe form of the aperture ; 

 zuegos^ a pair, referring to the arrangement of the zooecia. ) 



The ovicell is hyperstomial, its orifice is large, without rapport 

 with the operculum, and is closed by a special membrane. The aper- 

 tura is elliptical; two small cardelles separate the anter from the 

 somewhat smaller poster. The frontal is a tremocyst with small 

 pores. The zoarium is free; the zooecia are joined two by two. No 

 spines. Avicularia present. 



Genotype. — Hippozeugosella {Bactridiifm) hagenowi Eeuss IS-il. 



Range. — Priabonian-Miocene. 



HIPPOZEUGOSELLA TEGES, new species. 



Plate 4, fig. 5. 



Description. — The zoarium is free, erect, unilamellar, formed of 

 two longitudinal rows of zooecia ; on the dorsal the zooecia are con- 

 vex, alternate, and have the aspect of a mat. The zooecia are dis- 

 tinct, elongate, hexagonal; the frontal is convex and formed of a 

 tremocyst with very small pores. The apertura is orbicular and 

 formed of a large anter, and Avith a smaller poster separated by 

 two very small cardelles; the peristome is complete, broad, and 

 infundibuliform. On the peristome itself and near the zoarial axis 

 there is a small round avicularium provided with a pivot. Ovicell? 



i,r , » X \ha=0.\l mm. 



Measurements. — Aperture -, _ . ^ 



^ [ la— 0.11 mm. 



. fZ3= 0.70-0.75 mm. 

 Zooecia -, „ .„ 



\ Is =0.4:0 mm. 



Affinities. — The frontal pores are very small and are easily filled 

 up. The frontal and the dorsal are covered with very small granu- 

 lations. The formation of the, branches is effected by the union of 

 two zooecia arising from two superposed zooecia. 



Occurrence. — Upper Jacksonian (Zeuglodon zone) ; Cocoa post 

 office, Choctaw County, Alabama (very rare). 



Upper Jacksonian (Ocala limestone) : Chipola River, east of Mari- 

 anna, Jackson County, Florida (common). 



Type.— Cat. No. 62591, U.S.N.M. 



