NORTH AMERICAN EARLY TERTIARY BRYOZOA. 613 



globular, transverse, smooth. The deep zooecia are entirely hidden; their apertura 

 is alone visible. The submarginal zooecia are oblique, oriented ; the frontal is very 

 convex, smooth, and terminated by a double beak, of which one at least is avicu- 

 liferous; there are three small elliptical avicularia with pivot on the frontal; the 

 oral avicularium is curved and opens into the locella. The marginal zooecia are 

 oriented; the frontal is terminated by two aviculiferous beaks entirely hiding the 

 apertura; there is only one avicularium in the vicinity of the apertura; the apertura 

 is very oblique, and disposed at the base of the locella. The interzooecial avicu- 

 laria are elongated like the beak of a duck; the pivot separates a small pore in 

 crossing the subtriangular orifice; the mandible was lodged in two-thirds of a 

 calcified area. 



Affinities. In the interior on the apertura there are two small cardelles sep- 

 arating a large anter from a smaller, very concave and broader poster (fig. 24). 

 The apertura is very finely denticulated. 



Some zooecia are perforated in their median portion by a longitudinal tube, 

 the external relations of which have not been discovered because of the lack of 

 specimens. 



The marginal zooecia much resemble the Cellepora verrucosa Reuss, 1847. The 

 present species differs from it in the presence of two oral avicularia opening into 

 the locella. 



Occurrence. Middle Jacksonian (Castle Hay ne limestone) : Wilmington. North 

 Carolina (very rare). 



Cotypes. Cat. No. 64221, U.S.N.M. 



ANALYTICAL KEY TO HOLOPORELLA. 



,/The frontal is bordered with areolae 2. 



I The frontal is entirely smooth (new genus) 3. 



Zoarium discoidal H. discus. 



Ovicell fissured H, Jisswata. 



Two or three salient avicularia on frontal H. birostrata. 



Long peristomle H. peristomaria. 



Spines. Oral avicularium on the frontal H. seposita . 



No spines. Oral avicularium disposed laterally on the perittome H. granulosa. 



rNo oral avicularium or aviculiferous beak on the frontal H. crassicollis. 



\Avicularium or beak 4. 



I- No large interzooecial avicularia 6. 



[Large interzooecial avicularia 5. 



[Zoarium massive, very small zooecia H. micropora. 



' \Zoarium large and with hornlike processes; large aviculiferous umbo H. damicornis. 



r Avicularium of more than 0.20 mm. in length H. allirostris. 



\Avicularium of less than 0.20 mm. in length 7. 



rPedunculated avicularium between the superficial zooecia H. separata. 



\No salient avicularium 8. 



jSpines. Zoarium free H. separata. 



\No spines. Zoarium incrusting H. orbiculifera. 



According to the nature of the frontal there are really two distinct genera. We 

 have not formed them, because on the fossils not only are the areolae not always 

 visible, but also they are often closed. Moreover, our technique was too elementary.. 



