XORTH AMERICAN EARLY TERTIARY BRYOZOA. 451 



METROCRYPTA BUCCULENTA Canu and Bassler, 1917. 



Plate 58, figs. 1-10. 



1917. Metrocrypta bucculenla CANTJ and BASSLER, Synopsis American Early Tertiary Cheilo- 

 stome Bryozoa, Bulletin 96, United States National Museum, p. 49, pi. 5, fig. 2. 



Description. The zoarium is free, cylindrical, bifurcated. The zooecia are 

 elongated, large, little distinct; the frontal is convex, porous, formed of a tremo- 

 cyst placed on a thick olocyst. The peristomice is somewhat elongated, oval, its 

 lower point formed of a wide rimule-spiramen ; the peristomie is somewhat salient; 

 the apertura (interior) is much smaller, orbicular, very oblique. The oral avicu- 

 larium is very rare; it is quite large, prominent, triangular, adjacent to the peristo- 

 mice, provided with a pivot placed very low. 



Measurements. Peristomice (Ape=0.30-0.35 mm. ( Apertura Aa=0.15 mm. 



(exterior) 1^6=0.30 mm. [ (interior) Za=0.15 mm. 



. fZz=1.00mm. 

 Zooecia , 



U2=1.23mm. 



Variations. The zooecia are sometimes distinct and separated by a prominent 

 thread (fig. 3). The peristomie (fig. 6) is very wide and in proportion with the 

 size of the peristomice; the apertura being small, we are ignorant of the use of 

 the exaggerated development of this tube. The exterior and frontal walls are very 

 thick (figs. 6, 7) ; but the interior walls are thin and very fragile (fig. 10). In the 

 interior the apertura is almost invisible, because it is almost perpendicular to the 

 plane of the frontal (fig. 10). 



We have observed some interzooecial swellings ; they are globular, porous, pro- 

 vided with an orbicular orifice (fig. 9). They are superposed on the tremocyst 

 and always appear in connection with a peristomie (figs. 2, 8). Can this be the 

 ovicell? 



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

 Carolina (common). 



Cotypes. Cat. No. 62598, U.S.N.M. 



Genus OCHETOSELLA Canu and Bassler, 1917. 



1917. Ochetosella CANU and BASSLER, Synopsis American Early Tertiary Cheilostome 

 Bryozoa, Bulletin 96, United States National Museum, p. 49. 



The ovicell is hyperstomial and deeply imbedded in the distal zooecium. The 

 rimule-spiramen is replaced by a small canal supported by a peristomial projection. 

 The frontal is an olocyst perforated laterally by some areolao and covered by a 

 uniform pleurocyst. 



Genotype. Ochetosella jncksonica Canu and Bassler, 1917. 



Range. Claibornian, Jacksonian. 



At first glance, this genus appears close to Palmiccllarln, but this is an error. 

 The large avicularian mucro of that genus is replaced here by a small canal which 

 is evidently the equivalent of the rimule-spiramen of the other genera of the family 



