332 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Vicksburgian (Marianna limestone) : Near Claiborne, Monroe County, Alabama 
(rare). 
Geological distribution. — Miocene, South Australia. (Waters.) 
Habitat. — Atlantic: In the English Channel, off Madeira, Azores and Cape 
Verde Islands, Florida. Pacific: China seas (45 m.). Torres Strait, Amirante 
(36-140m.), Saya de Malha (48-200 m.), Mauritius. Wasin (16 m.), British East 
Africa. 
Plesiotypes. — Cat. No. 64266, U.S.N.M. 
Fig. 95. — Genas Haplopoma Levinsen, 1909. 
A-I. Haplopoma impressum Audouin, 1826. A. Free larva in profile, X 75. B. View of 
larva, aboral face, X 75, showing the arrangement of the striations of the terminal bud. C. 
Oral face of larva, X 75, exhibiting the general form of the stomach. (A-C after Barrois, 
1877. ) ce, orifice of the internal sac ; est, stomach ; o, mouth of the gastrula ; pli, pharynx ; pi, 
ciliary plume ; RV, border of the terminal bud ; vt, terminal bud. D. Group with primary 
zooecium (=ancestrula), X 55. In the margin of the zooecia internal dietellae are visible. 
E. The operculum of the ancestrula of fig. D, X 140. F. Zooecia with ancestrula, X 55. 
G. Operculum, X 140. H. Operculum of the ancestrula of fig. F, X 140. I. View from the 
basal surface. The zooecia and the kenozooec-ia surrounding the ovicells are furnished with 
dietellae, X 40. (D-I after Levinsen, 1909.) 
Genus HAPLOPOMA Levinsen, 1909. 
Zoological bibliography. — 1877. Barrois, Recherches sur l’embryologie des Bryozoaires, p. 171, 
pi. 9, figs. 1-3. — 1909. Levinsen, Morphological and Systematic Studies on the Cheilosto- 
matous Bryozoa, p. 2S0, pi. 18, fig. 11; pi. 22, figs. 9, 10. 
The frontal of the zooecia is garnished with scattered pores; it is perforated 
by a median ascopore opening into the compensation sac. The operculum is simple. 
The ovicell is closed by the operculum. The ancestrula has no ascopore, but the 
aperture bears a rimule which opens into the compensation sac. Fifteen tentacles. 
Genotype.— Haplopoma ( Flustra ) impressa Savigny- Audouin, 1826. 
Range. — Tortonian-Recent. 
