530 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Variations. The apertura of the ovicelleil zooecia is twice as large 

 (/=0.40mm.). 



In this species, as in the preceding- Cheilopora, many of the apertures are 

 closed by a smooth, calcareous lamella. We have examined this lamella in the 

 interior; it is there quite distinctly visible, placed at the middle of the peristomie; 

 it is not in direct continuity with the olocyst. We do not think that it represents 

 a calcareous operculum. but it is probably the closure of the diseased zooecia 

 which have lost their polypide. This is evidently only a hypothesis. 



We can not affirm that the oral avicularia are true avicularia. for certain 

 ones among them have much resemblance to the auriculate vibracula. 



Affinities. This species much resembles Cheilopora sailJans, but differs from 

 it in its quite manifestly transverse apertura. 



It differs from Cheilopora transversoides in its nonsymmetrical apertura. in 

 its larger micrometric dimensions, and in the very large apertura of its ovicelled 

 zooecia. 



Occurrence. Middle Jacksonian: Wilmington. North Carolina (common); 

 near Lenuds Ferry. South Carolina (rare). 



Holotype.CsA. Xo. G4179, U.S.N.M. 



CHEILOPORA TRANSVERSOIDES, new species. 



Plate 68, figs. 6-8. 



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

 to back, and inseparable. The zooecia are distinct, elongated, lozenge-shaped, or 

 ogival, separated by a salient thread, wide and variable; the frontal is convex and 

 formed of a tremocyst with numerous pores placed on an olocyst finely perforated 

 with pores corresponding to the tremopores. The apertura is transverse, elliptical, 

 symmetrical ; the anter is perceptibly equal to the poster ; there are two strong 

 median cardelles. The ovicell is endozooecial, small, little salient, convex, smooth. 

 The two oral avicularia are small, suborbicular, little salient. 



fAa=0.14-0.18mm. . [2=0.90-1.00 mm. 



Measurements. Apertura i, ., Zooecia, nnnm 



1 70=0.18-0.24 mm. 1/3=0.60-0. < mm. 



Variations. The apertura of the ovicelled zooecia is identical with the apertura 

 of the ordinary zooecia. 



In the interior we have observed that the two cardelles are only the extremities 

 of two condyles, supported on the zooecial walls. The two dietellae are also very 

 constant. The zooecial walls are very thin. 



Affinities. This species differs from Cheilopora, transversa in its symmetrical 

 apertura, in its smooth and much smaller ovicell. and in its smaller micrometric 

 dimensions. 



It differs from Cheilopora saillans in its transverse and not suborbicular aper- 

 tura, and in its ovicells with small orifice. 



