68 BULLETIN 96, UNITED STATES NATIONAL MUSEUM. 



OoGurrence. — Middle Jacksoniiin (Castle Hayne limestone) : Wil- 

 mington, North Carolina (rare). 

 Type.— Cat No. 62607, U.S.N.M. 



PERIGASTRELLA, new genus. 



(Peri, around; gasfer, stomach.) 



The apertura is semicircular. The thick band of the operculum 

 is on the border. The frontal is surrounded by one or two rows of 

 small areolae; it is formed of an olocyst supporting a smooth or finely 

 granular pleurocyst. Spines. 



Genotype. — PerigastreJla (Lepralia) lahiata Bceck, 1861. 



Range. — Lutecian — Recent. 



This genus is abundantly represented in the Claibornian, eTack- 

 sonian. and Vicksburgian of the Southern States, Perigastrella 

 {Cellepora) cycloris Gabb and Horn, 1862, and 13 new species being 

 known. 



PERIGASTRELLA OVOIDEA, new species. 

 Plate 6, fig. 8. 



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

 tinct, elongated, large, ovoid; the frontal is very convex, bordered 

 by three small areolar pores, and formed of a very finely granular 

 pleurocyst, almost smooth. The apertura, almost invisible exteriorly, 

 is trapezoidal and oblique ; the peristomie is deep : the peristome is 

 very oblique and bears 6-8 spines; it is sometimes interrupted in 

 front, but more often it bears a salient mucro, oblique or erect, 

 hiding more or less the apertura ; there is small lyrule in the aper- 

 tura. The ovicell is small, salient, globular, almost entirely de- 

 tached from the distal zocecium: it is hyperstomial and recumbent; 

 its frontal is finely granular, like the zooecia. The ancestrula is 

 very small, but identical in form with the other zooecia. 



1^,7=0.05 mm. 



Measurements. — Apertura \ja=O.QQ-0.\0 mm. 



f 7:^=0.75-0.80 mm. 

 Zooecia |^,^0 50 „,m. 



Afinities. — ^This beautiful species is quite recognizable by its very 

 large zotrcial convexity. Tt differs from Perk/a.^freNa seimerecta 

 Koschiusky, 1885, in the presence of spines and in its somewhat 

 larger dimensions. 



Occurrence. — Middle Jacksonian: Eutaw Springs, South Caro- 

 lina (common). 



Upper Jacksonian: Railroad wharf at Bainbridge, Georgia 

 (common). 



Type.— Cat. No. 62613, U.S.N.M. 



