586 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Genus HEMICYCLOPORA Norman, 1894. 



1S94. Hcmicyclopora NORMAN, A Month on the Trondhjem Fiord, Annals and Magazine 

 Natural History, ser. <>, vol. 13, p. 124. 



The ovici-11 is recumbent. The apertura is provided with very low cardelles 

 and formed of a large anter and of a small concave poster. The frontal is smooth 

 and formed of an olocyst. Spines. 



Genotype. Hemicyclopora (Lepralia) polita Hincks, 1880. 



Range. Hel vet i an Recent. 



Another known recent species is flemicydopora (Lepralia) labiosa Jullien, 

 1903. 



The only known fossil species is Hemicyclopora o'beliscus Manzoni, 1875. 



HEMICYCLOPORA PARAJUNCTA Canu and Bassler, 1917. 

 Plate T4, figs. 2. 3. 



1917. Hcmiciicloponi purajuncta CANU and BASSLER, Synopsis of American Early Tertiary 

 Cueilostorne P.ryozoa, Bulletin 96, United States National Museum, p. 69. pi. 6, fig. 6. 



Description. The zoarium incrusts shells. The zooecia are distinct, some- 

 what elongated, ogival; the frontal is somewhat convex and absolutely smooth. 

 The apertura is oblique, suborbicnlar; the peristome bears 8 distal spines and a 

 proximal small mucronoid lip. The ovicell is globular, very salient, smooth, very 

 little joined to the distal zooecium; it is recumbent, hyperstomial. 



f/i=0.10mm. . [7,2=0.50-0.55 mm. 



Measurements. Apertura 1 7 /jooecia,, A , A -. KK 



Ua=0.09 mm. lfe=0.40-0.5o mm. 



Affinities. This species offers the exterior aspect of Pci-i<i<ixtn'Jl<t with very 

 small areolae which generally appear smooth. 



It differs from Perigastrella depresfta in the presence of the small labial 

 mucro and in its ovicell almost completely detached from the distal zooecium. 



It, differs from Per'ujaxtreTla trapezoidea in the absence of areolae and in its 

 much smaller ovicell more detached from the distal zooecium. 



Occurrence. Middle. Jacksonian : Near Lenuds Ferry, South Carolina (com- 

 mon). 



Cotypes.C&t. No. 62610, U.S.N.M. 



Genus MASTIGOPHORA Hincks, 1880. 



1880. Mastigopliora HINCKS, British Marine Polyzoa, p. 278. 



The ovicell is small and recumbent. The apertura is semilunar; its proximal 

 border is straight and bears a rimule elongated and rounded. The frontal is a 

 tremocyst with small pores placed on an olocyst. Vibracula. 



Genotype. Mastigophora ht/ndmanni Johnston, 1S4T, and Mastigophora 

 (Flustra) dutertrei Savigny-Audouin, 1826. Lutetian Recent. 



The fossil species of this genus are : 



Pachycraspedoum zittcll Koschinsky, 1885. 



Pachycraspedoum lautum Koschinsky, 1885. 



