730 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Variations. The quincunx arrangement of the peristomes is very irregular 

 and it is not rare to find them adjacent to each other. The oeciostome appears 

 to open into the peristomie of the tube to which it is attached, but this is only an 

 illusion, for by scraping it with a scalpel we were able to verify that it really 

 opens into the ovicell. 



Ajft-niti.es. This species is easy to determine on account of its much com- 

 pressed branches. It differs from Mecynoeda brevis, in which this character ap- 

 pears, in the absence of the long peristomies and in its much elongate ovicell. 



Occurrence. Vicksburgian (Marianna limestone) : One mile north of Monroe- 

 ville, Alabama (rare). 



Cotypes. Cat. No. 65462, U.S.N.M. 



MECYNOECIA QUISENBERRYAE, new species. 



Plate 156, figs. 26-30. 



Description The zoarium is an Entalophora with cylindical and bifurcated 

 branches. The tubes are little visible, garnished with transverse, overlapping 

 wrinkles, arranged in quincunx or in oblique verticells; the peristome is thick, 

 orbicular, little salient. The ovicell is very elongate, symmetrical, smooth; the 

 oeciostome is supported on the tube and has the form of a lunar crescent. 



Diameter of the peristome 0.18-0.20 mm. 



Distance between the peristomes 0.50-0.60 mm. 



Separation of the peristomes^-. .___ 0.50-0.60 mm. 



Diameter of the branches 1.00 mm. 



Affinities. This species is very close to Mecynoeda 1 mutt a in the general ar- 

 rangement of the tubes. It differs from it in its larger peristome (more than 0.16 

 mm. ) and in its tubes which are closer together. 



We dedicate this species to Miss Adelaide C. Quisenberry, of the United States 

 National Museum, in appreciation of her help and interest in the preparation of 

 this work. 



Occurrence. Vicksburgian (Marianna limestone) : Salt Mountain, 5 miles 

 south of Jackson, Alabama (common). 

 Cotypes. Cut. No. 65396, U.S.N.M. 



MECYNOECIA LUNATA, new species. 



Plate 156, figs. 1-8. 



Description. The zoarium is an Entalophora, regularly cylindrical and bifur- 

 cated. The tubes are distinct, cylindrical, separated by a little salient thread ; the 

 peristomes are thick, orbicular, arranged in quincunx or in Peripora. The ovicell 

 is very elongate, very finely punctate; the oeciostome is very large, transverse, at- 

 tached to a tube and has the form of a lunar crescent. 



