36 BULLETIN m, UNITED STATES NATIONAL MUSEUM. 



ACANTHOCELLA ERINACEA. new species. 



Plate 4, fig. 1. 



Description. — The zoarium incrusts shells and bryozoa or creeps 



over algae. The zooecia are distinct, very slightly elongated, sub- 



circnlar; the frontal is very convex; the costules are thick, separated 



by the lacunae, ornamented by three, very prominent, hollow spines 



corresponding to the lumen pores. The apertura is semilunar with 



a straight proximal border; the peristome is distal and bears four 



large, hollow spines. The ovicell is hyperstomial, buried in the distal 



zooecia, globose, not closed by the operculum, ornamented with small, 



remote punctations. 



,, ^ . ^ \ha=O.Od mm. 



Measurements. — Aperture { , ,. ^ ^ ,. ^ ^ 



^ 1^=0.11-0.12 mm. 



fZs=0.75-0.80 mm. 



Zooecia , , n -n n^- 



Z2!=0.o0-0.6o mm. 



Variations. — The sharp points which decorate this species give it 

 the spinous aspect of the hedge hog. It is very variable in its micro- 

 metrical dimensions and its gemmation; the zooecia are oriented in 

 the most unexpected and divergent manner. 



Occurrence. — Middle Jacksonian (Castle Hayne limestone) : Wil- 

 mington, North Carolina (rare). 



Type.— C2ii. No. 62587, U.S.N.M. 



CRIBRENDOECIUM, new genus. 



(Abbreviation of " Cribrilina with endozocecial ovicell.'') 



The ovicell is endozocecial. The costules are separated by a small 

 initial slit and some medium sized lacunae ; they have no lumen pores. 

 The apertura is formed of a semilunar anterior portion and a larger 

 and concave posterior part separated by two cardelles. The apertura 

 of the ovicelled zooecia is larger. Large interzooecial avicularia are 

 present. 



Genotype. — Crihrendoeciuni tenuicostulatum, new species. Jack- 

 sonian. 



CRIBRENDOECIUM TENUICOSTULATUM, new species. 



Plate 4, tig. 2. 



Description. — The zoarium incrusts shells. The zooecia are dis- 

 tinct, elongated, separated by a furrow, elliptical, fusiform; the 

 frontal is convex ; the costules are very thin, niuiierous, without lumen 

 pores, and separated by very small lacunae. The aperturae of the 

 ordinary zocecia are formed of a semilunar anterior and a verj^ large, 

 straight posterior part separated by two small cardelles; the aper- 

 tura of the ovicelled zocecia is larger and its posterior portion is 



