Measurements. 



Measurements. 



666 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



sometimes regularly rectilinear; they never commence with an isolated zooecium. 

 The distance apart of the zooecia in quincunx is from 0.40 to 0.50 mm. 



Maximum width of zoarium 1.6 mm. 



Length of tube 0.40-0.50 mm. 



Diameter of peristome 0.10-0.12 mm. 



Affinities. In the arrangement of its tubes and in the aspect of the zoarimn, 

 this species much resembles Proboscina coliibra; it differs from it in its much smaller 

 micrometric measurements. 



Occurrence. Upper Jacksonian (Ocala limestone) : Chipola River east of 

 Marianna, Jackson County, Florida (rare). 



CotypesC&t. No. 65290, U.S.N.M. 



PROBOSCINA RECTALINEA. new species. 



Plate 152, figs. 3-7. 



Description. The zoarium is multiserial and incrusts shells in linear branches. 

 The tubes are little distinct, cylindrical, arranged in quincunx, feebly striated trans- 

 versally. The peristome is thin, salient, orbicular, somewhat oblique. 



Maximum width of zoarium 0.80 mm. 



Length of tube 0.35-0.48 mm. 



Diameter of peristome 0.12 mm. 



Variations. The first branches are triserial; they never start with an isolated 

 zooecium. The branches are directed in a straight line with remarkable regularity. 

 The protoecium is orbicular and very small ; its diameter is 0.12 mm. 



Affinities. The tubes are of the size of those of Proboscina exigua, but the 

 present species differs from it in its much more salient peristome, and in its zooecia 

 arranged in more crowded quincunx. 



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

 south of Jackson, Alabama (rare). 



Cotypes.C'&t. No. 65376, U.S.N.M. 



PROBOSCINA CONVENIENS, new species. 



Plate 152, figs. 10-12. 



Description. The zoarium is multiserial and incrusts shells; the branches are 

 arranged symmetrically on each side of the ancestrula; they have the form of an 

 elongate palm leaf. The tubes are indistinct, arranged in regular quincunx. The 

 peristome is thick, salient, orbicular. 



Maximum width of zoarium 1.00 mm. 



Measurements. Length of tube 0.30 mm. 



Diameter of peristome 0.12 mm. 



Affinities. This species much resembles Diaperoecia clava, new species, but 

 differs in its much thicker peristome and in its micrometric measurements. We be- 

 lieve that the discovery of the ovicell of this species would classify it in Diaperoecia. 



