62 PKOCEEDINGS OF THE NATIONAL MUSEUM vol.72 



Genus MICROPORA Gray, 1848 



MICROPORA CORIACEA Esper, 1791 



Text Figure Be 



1873. Micropora coriacea Smitt, Floridan Bryozoa. pt. 2. Kongl. Svenska 

 Vetenskaps-Akademiens Handlingar, vol. 11, no. 4, p. 13, pi. 2^ 

 fig. 74. 



1920. Micropora coriacea Canu and Bassler, North American Early Terti- 

 ary Bryozoa. Bull. 106, U. S. National Museum, p. 235, pi. 4 

 figs. 20-22. (Bibliography, geographic and geologic distribution. ) 



,, . ^ . jha = O.OQ mm. 



Measurements. — Aperturei, 



^ Ua = 0.12 mm. 



rj . 1X2 = 0.44-0.50 mm. 

 ZiOoeciai, _ „„ ^ _^ 



Us = 0.26-0.30 mm. 



Variations. — Our micrometric measurements are a little less than 

 those exhibited on the fossil specimens; they, however, conform to 

 the usual variations of the species. 



The aperture is closed by a true light-colored very simple opercu- 

 lum which we have illustrated. Smitt gave its length 0.12-0.16 mm. 

 in conformity with our measurements. 



Biology. — Our specimens encrust shells and nuliipores. Many of 

 them were living and ovicelled in March and April, 1885. 



Occurrence. — Albatross Station D. 2405, Gulf of Mexico; 28° 45' 

 00" N.; 85° 02' 00" W.; 30 fms.; gray sand, broken 

 coral. 

 Albatross Station D. 2639, Straits of Florida; 25° 04' 



50" N.; 80° 15' 10" W.; 56 fms.; coral sand. 

 Florida, 58 to 218 meters (Smitt). 



Family CALPENSIIDAE Canu and Bassler, 1923 

 Genus HEMISEPTELLA Levinsen, 1909 



HEMISEPTELLA DENTICULATA Smitt, 1873 



Plate 9, Figure 9 



1873. Biflustra denticulata Smitt, Floridan Bryozoa. Kongl. Svenska Veten- 

 skaps-Akademiens Handlingar, vol. 11, no. 4, p. 18, pi. 4, figs. 

 89-91. 



Measurements (after Smitt) . — 



Operculum , ""n . n 



1/0 = 0.10 mm. 



fig = 0.58 mm. 



Zooecia , 



Us = 0.28 mm. 



Structure. — The figures of Smitt are perfectly exact. We class the 



species in Hemiseptella because of the presence of opesial spicules, but 



we have not seen the trace of opesiular muscles on the ectocyst. The 



