728 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



(peristome=0.10 and not 0.16 mm.) than Mecynoecia lunata, in which the branches 

 are also quite cylindrical. 



Occurrence. Middle Jacksonian: Wilmington, North Carolina (very com- 

 mon) ; near Lenuds Ferry, Soiith Carolina (rare) ; 18 miles west of Wrightsville, 

 Johnson County. Georgia (very rare) ; 8^ miles north of Grovania, Georgia (rare). 



Cotypes.C&i. No. 65465. U.S.N.M. 



MECYNOECIA PUSILLA, new species 



Plate 127, figs. 19-22. 



Description. The zoarium is a small bifurcated EntalopTiora. The tubes are 

 distinct, cylindrical, convex; the peristomes are salient, thin, oblique, orbicular, 

 arranged in irregular quincunx. The ovicell is elliptical, very long, striated trans- 

 versally ; the oeciostome is elliptical, large, salient. 



Diameter of the peristomc 0.10 mm. 



Meamrem en ts. 



Distance between the peristomes 0.50-0.70 mm. 



Diameter of the branches 0.40 mm. 



This is a small species provided with very large ovicell. We might suppose 

 that it was very prolific and coarse, but this is not so, as it is very delicate and its 

 life was ephemeral. This is within the domain of the pathologist who must 

 search for the causes of these unexpected occurrences. It is the smallest species 

 of the genus. 



Occurrence. Middle Jacksonian: Near Lenuds Ferry, South Carolina (very 

 rare) ; 3^ miles north of Grovania, Georgia (very rare). 



Upper Jacksonian (Ocala limestome) : Chipola River, east of Marianna, Jack- 

 son County, Florida. 



Cotypes.Cnt. Nos. 65470. 65471, 65484, U.S.N.M. 



MECYNOECIA BREVIS, new species. 



Plate 127, figs. 8-18. 



Description. The zoarium is an Entalophora with branches claviform, com- 

 pressed, and bifurcated. The tubes are cylindrical, distinct, little convex, termi- 

 nated at their extremity by a long peristomie upward bent; the peristomes are 

 orbibular, thick, and arranged in irregular quincunx. The ovicell is large, short, 

 very finely porous; the oeciostome is elliptical, transverse, attached to the peristome 

 of a tube. The zone of growth is very short and rounded. 



Diameter of the peristome 0.16 mm. 



Diameter of the orifice 0.10 mm. 



Diameter of the tubes 0.20 'mm. 



Distance between the peristomes 0.40-0.60 mm. 



Maximum length of the peristomie 0.40 mm. 



Variations. The zoarium is formed of claviform branches sometimes termi- 

 nated by irregular ramifications ; cylindrical branches are rare. The length of 



Measurements.- 



