222 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Affinities. This is the largest known species of Floridina. This character 

 and the large teeth in the opesium of. its onychocellarium distinguish it clearly 

 from Floridina antiqua and from F. laguncula. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, 

 North Carolina (common). 



Holotype.C&i. No. 63983, U.S.N.M. 



FLORIDINA ANTIQUA Smitt, 1873. 

 Plate 35, figs. 10-18. 



18T3. Mollia antiqua SMITT, Floridan Bryozoa, Kongl. Sveuska Vetenskaps-Akademie 

 Handlingar, vol. 3, p. 12, pi. 2, fig. 73 (not Busk). 



Description. The zoarium is unilamellar, creeping over algae. The zooecia 

 are broad, distinct, ogival in shape ; the cryptocyst is a little concave and very finely 

 granulated; the polypidian convexity is a continuation of the cryptocyst; the 

 opesium is subtrifoliate and contracted by two large lateral teeth which separate 

 the opercular part from the opesiular portion. The opesiular indentations are 

 large and wide; they are often transformed into true, nearly complete linear 

 opesiules by the union of the opesial process with the polypidian convexity. The 

 ovicell is a distal convexity little apparent, but clearly distinct from the cryptocyst 

 of the distal zooecium. The onychocellarium is larger than the zooecium, elon- 

 gated, with a submandibular area rounded but little developed ; its opesium is 

 oval, the pointed end at the top, much denticulated. 



Measurements. Opesium f ^0=0.20-0.24 mm. fZs=0.50mm. 



(including opesiules)lfo=0.20-0.24mm. \1s=OAO mm. 



.-.,,,. r0n=0.60mm. 

 Onychocellarium 



Variations. Interzooecial communication appears to be effected by a distal 

 septula and 4 pairs of lateral septnlae (fig. IS). The cryptocyst is as usual, formed 

 from elements of the olocyst (fig. 18). 



In the interior (fig. 16), the form of the opesium is the same; we note further 

 that there are two tuberosities roughly outlining laterally a polypide tube. The 

 proximal margin of the opesium of the onychocellarium is thickened. 



The union of the opesial processes with a polypidian convexity is frequent 

 (fig. 18). On the more perfect specimens the length of the polypidian convexity 

 is from 0.06 to 0.08 mm.; its width, is from 0.14-0.16 mm. (fig. 11). It often 

 diminishes in length without apparent reason and even disappears (fig. 12). 



The size and aspect of the zooecia vary greatly. Figures 13, 14, 15 are taken 

 from the same zoarium, where there may be noted broad zooecia with a reduced 

 cryptocyst, smaller zooecia with the cryptocyst much developed, and again very 

 narrow zooecia. Usually most of the zooecia are broad, and most of the opesiules 

 ure large and incomplete. 



The zoarium sometimes incrusts shells; the polypidian convexity is then little 

 apparent, and the opesiules are quite large. 



