50 BULLETIN 9G, UNITED STATES NATIONAL MUSEUM. 



ported by a peristomial projection. The frontal is an olocyst per- 

 forated laterally by some areolae and covered by a uniform pleu- 

 rocyst. 



Genotype. — OchetoseUa jacksonica., new species. 



Range. — Claibornian, Jacksonian. 



At first glance, this genus appears close to Palmicellaria., 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 Stomachetosellidae. 

 Wlien it exists, the oral avicularium is indeed in its place in the im- 

 mediate vicinity of the peristomice and of the rimule-spiramen. 



OCHETOSELLA JACKSONICA, new species. 



Plate o, fig. 3. 



Description. — The zoarium is free, erect, cylindrical, bifurcated, 

 often anastomosing. The zocecia are elongated, distinct, hexagonal, 

 separated by a salient thread; the frontal is concave, bordered by 

 large areolae, formed of a thin olocyst and covered by a uniform and 

 finely granulated pleurocyst. The apertura is semilunar and invisible 

 externally; the peristomice is very oblique, with undefined outlines, 

 vaguely triangular. The ovicell is globular and deeply embedded in 

 the distal zocecia. The oral avicularium is rare. 



Measurements. — Zooecia |^^__q ^q i^m. 



Occurrence. — Upper Claibornian (Gosport sand) : One mile south- 

 west of Rockville, Clarke County, Alabama (very rare). 



Lower Jacksonian : Jackson, Mississippi (very common). 



Middle Jacksonian : Wilmington, North Carolina (very common), 

 and various localities in South Carolina and Georgia. 



Type.—Coi. No. G2599, U.S.N.M. 



Family SMITTINIDAE Levinsen, 1909. 



The ovicell which is hyperstomial and embedded in the distal 

 zocecia opens into the peristomie. The peristome is produced and 

 channeled in front. The operculum is (not universally) very thin; 

 the lower edge is straight or slightly curved inward and hardly 

 separated from the ectocyst; the muscular attachments are usually 

 a ridge on the border. There are very small oral glands often partly 

 attached to the tentacular sheath. Spines. 



This family is a very natural one, but unfortunately our knowl- 

 edge of the anatomy and embryology is too slight to allow us to fix 

 its exact limits. The development of the peristome is one of the 

 essential characters ; we continue to employ the same terminology as 

 for the preceding families. The orifice of the peristome is the 



