NORTH AMERICAN EARLY TERTIARY BRYOZOA. 293 



CRIBRILINA RATHBUNAE, new species. 



Plate 5, figs. 15-17. 



Description. The zoarium incrusts other bryozoa. The zooecia are elongated, 

 distinct, elliptical; the cribriform area is somewhat convex and formed t>f trans- 

 verse costules; the lacunae are large and prominent, 1 to -2 to each pair of adjacent 

 costules. The aperture is semilunar. transverse, bordered by a thin, smooth, i in- 

 prominent peristome. The two small oral avicularia are simple, peristomial. and 

 without pivot. 



e { * fl = ; n 7 nim ' Zooeciaif *=j">-** "" 



I7a=0.10nun. us=0.2omm. 



Variations and affinities. The lacunae are variable in number on each zooe- 

 cium : their prominence is much lessened by fossilization. 



This species differs from CrilirRina verrucosa in its smaller zooecial dimen- 

 sions and its less convex cribriform area. 



This interesting species is named in honor of Miss Mary J. Bathbun. of the 

 United States National Museum, as a slight appreciation of her valuable work upon 

 marine invertebrates. 



Occurrence. Midwayan: Mabelvale. near Little Eock, Arkansas (very rare). 



Cotypes.C-Ai. No. 63813, U.S.N.M. 



Genus PUELLINA Jullien, 1886. 



1S86. PueUina JULLIEN, Les Costulidees. Bulletin Socite Zoologique France, vol. 11, p. 7. 

 Bibliography (Anatomical). 1902. HARMER, On the Morphology of the Cheilostomatn. Quar- 

 terly Journal of Microscopic Science, vol. 4t;. pp. 2, 293, 326, pi. 15. fig. 7. 1903. NORMAN, 

 Notes on the Natural History of East Finmark, Annals Magazine Natural History, ser. 7, 

 vol. 12, p. 96, pi. 9, figs. 3, 4, 5. 1909. LEVINSKN, Morphological and Systematic Studies on the 

 Cheilostoniatous Bryozoa, p. 159, pi. 9. fig. 12. 



The lacunae between the costules are very small; the lumen, more or less visible, 

 bears many pores, of which the first in the shield is larger than the others. The 

 aperture is semicircular. The operculum is simple and entirely chitinous. The 

 ovicell is hyperstomial and always closed by the operculum. Between the costular 

 shields are papillae. The dietellae number at least three lateral pairs. 



Irt-notypes. PueUina (CrU/rHina) aattyae Busk. 1852. and Piiclli/i<i (< riliri- 

 liufi) radiata Moll, 1803. 



Range. Senonian-Eecent. 



The papillae are short, tentaculiform evaginations. The first pair, near the 

 aperture, is always the larger by far. They have been considered as true avicularia 

 (Jullien) as sensorial vibracula (Smitt) or as simple appendages corresponding to 

 the spines of the ancestrula (Harmerl. Their place is almost invisible on the 

 fn^ils. Levinsen limits this genus to species provided with an interzooecial 

 uvieularium. However, it would be difficult for us to classify our PucWna bij-'nosa 

 and PueUina simulator in another eenus. 



