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 (16m.), British East 

 Africa. 



Plesiotypes.Ca.t. No. 64266, U.S.N.M. 



J 40 



FIG. 95. Genus 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 7n, 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 ; /)/(, pharynx; pi, 

 ciliary plume ; KV, 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 kenozooecia surrounding the ovicells are furnished with 

 dietellae, X 40. (D-I after Levinsen, 1909.) 



Genus HAPLOPOMA Levinsen, 1909. 



Zoological bibliography. 1877. BARROIS, Recherches sur I'embryologie des Bryozoaires. p. 171, 

 pi. 9, figs. 1-3. 1909. LEVINSEN, Morphological and Systematic Studies on the Cheilosto- 

 matous Bryozoa, p. 280, pi. IS, 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. 



