158 PROCEEDINGS OF THE NATIONAXi MUSEUM vol.72 



Affinities. — The figured specimen only has been found but it was 

 interesting to us because of its great vigor. Prohoscina parviangulata 

 Canu and Bassler, 1920, can alone be compared with it but it differs 

 from that species in its more closely spaced peristomes and in the 

 occasional presence of paired tubes. 



The branches enlarge before bifurcating and they bear three or 

 four rows of tubes. 



Occurrence. — Albatross Station D. 2319, north of Cuba; 23° lO'^ 

 37" N.; 82° 20' 06" W.; 143 fms.; gray coral. 



Eolotype.—C&t. No. 7572, U.S.N.M. 



Family ONCOUSOECIIDAE Canu, 1918 



Genus ONCOUSOECIA Canu, 1918 



ONCOUSOECIA ARCUATA, new species 



Plate 31, Figure 2 



Description. — The zoarium encrusts shells; the branches are long, 

 somewhat arched, claviform, mono to triserial. The tubes are thin, 

 rather long, little visible, striated transversely. The peristome is thin, 

 orbicular, little salient. The ovicell is globular, as wide as the branches; 

 the oeciostome is terminal, a little smaller than the peristome. 

 Measurements. — Diameter of orifice, 0.10 mm. 



Diameter of peristome, 0.12 mm. 

 Distance of peristomes, 0.72 mm. 

 Diameter of branches (at the extremity), 0.60 mm. 

 This species is very well characterized by its globular ovicells. 

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

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

 Eolotype.—C&t. No. 7564, U.S.N.M. 



Genus PERISTOMOECIA Canu and Bassler, 1920 



PEKISTOMOECIA FLORIDANA, new species 



Plate 31, Figures 6-9 



Description. — The zoarium encrusts dead shells; the branches are 

 formed of small successive palm-shaped areas and are dichotomous. 

 The tubes are visible, cylindrical, striated transversely, terminated 

 by a very long free and erect peristome. The peristome is thin,, 

 orbicular, or oval. The ovicell is orbicular, convex, with a small 

 salient oeciostome at the center. 



Measurements. — Diameter of orifice, 0.06 mm. 



Diameter of peristome and of tubes, 0.08-0.10 mm.. 



Separation of peristomes, 0.50 mm. 



Distance of peristomes, 0.50 mm. 



Affinities. — All the Berenicea forms resemble each other, and when 



the micrometric dimensions are close their differentiation is very 



difficult. In order to separate them accurately it is necessary to 



