BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Genus RHAMPHOSTOMELLA Lorenz, 1886. 



18SG. Rhamphostomella LORENZ, Bryozoen von Jan Mayen, Die Oesterreichische Polarstation 

 Jnn Mayen, vol. 3, p. 11. 



^ C J Lx 



b*a3 Tx83 



P ,250 Q * 251 



FIG. 134. Genus Rhamphostomella Lorenz, 1886. 



A-G. Rhamphostomella costata Lorenz, 1886. A. Zooecia, X 30. (After Lorenz, 1886.) 

 B. Section showing the oral glands terminating near the diaphragm, X 85. C. Gland, X 250. 

 D, E Operculum and avicularian mandible, X 85. (B-E after Waters, 1900.) F, G. Oper- 

 culum and avicularian mandible, X 60. (After Lorenz, 1886.) 



H-K. Rhamphostomella plicata Smitt, 1867. H. Ovicell and the anterior part of the 

 zooecium, X 50. (After Nordgaard, 1906.) I, K. Operculum and avicularian mandible, X 

 85. (After Waters, 1900.) J. Avicularian mandible, X 83. 



L. Avicularian mandible, X 85. 



M, N. Rhamphostomella contigua Smitt, 1S67. Operculum and avicularian mandible, X 83. 



O. Rhamphostomella scabra Smitt, 1867. Avicularian mandible, X 83. (J-O after Nord- 

 gaard, 1905.) 



P, Q. Rhamphostomella radiatula Hincks. 1877. Avicularian mandibles, X 250. (After 

 Lorenz, 1886.) 



R. Rhamphostomella bilaminata Lorenz, 1886. Avicularian mandible, X 150. (After 

 Lorenz, 1886.) 



S, T. Rhamphostomella spinigera Lorenz, 1886. Different forms of lyrula, X S3. (After 

 Nordgaard, 1906.) 



The operculum closes the ovicell. which is hyperstomial ; it is thin and delicate, 

 but there is a raised circular ridge. There is a very narrow lyrula. before an 

 asymmetrical sinus. The frontal is a pleurocyst with costules. Before the orifice 

 of the ovicell and at the same height, there is a very large avicularium. oblique. 



