FORAMINIFEEA OF THE ATLANTIC OCEAN, 103 



Tills species is described by Brady as follows : 



Test free; composed of a nonseptate tube wound upon itself, not regularly and 

 symmetrically, so as to retain a rectilinear contour, but in curved or twisted fashion, 

 80 as to form an arcuate or subhelicoid test. Shell wall very thin; exterior some- 

 what rough, interior smooth and polished. Longer diameter, one-fifth inch (5 mm.) 

 or more. 



Distnhution. — The types of the species are from one of the Porcupine 

 stations, in 358 fathoms, off the British Isles and similar specimens 

 more or less injured and therefore not clearly identifiable from the 

 Challenger material in the south Atlantic off Buenos Aires in 1,900 

 fathoms. 



The figured specimen (pi. 38, fig. 1) is from the type station in the 

 collection of the United States National Museum received from 

 Doctor Carpenter. 



The large size with the thin fragile test and peculiar type of irregular 

 coUing distinguish it from other Imown species. 



EXPLANATION OF PLATES. 



Plate 1. 



Fig. 1. Astrorhiza limicola. X 8. (After Brady.) 



2. Astrorhiza limicola. X 8. Specimen laid open to show the interior. (After 

 Brady.) 



Plate 2. 



Figs. 1-3. Astrorhiza arenaria. X 15. Photographs of three variously shaped speci- 

 mens. 



Plate 3. 



Fig. 1. Astrorhiza arenaria. X 15. Photograph of broad flattened specimen. 

 2. Astrorhiza angulosa. X 15. Photograph of quadrate specimen. 



Plate 4. 



Figs. 1-3. Astrorhiza angulosa. X 10. Photographs of variously shaped specimens. 



Plate 5. 



Figs. 1-3. Astrorhiza venniformis. X 15. Photogiaphs of dried specimens showing 

 the characteristic cracks of the exterior. 

 A. Astrorhiza granulosa. X15. Photograph of typical specimen. 



Plate 6. 



Fig. 1. Rhabdammina abyssorum. X 15. Photograph of quadrate specimen. 



2-5. Rhabdammina cornuta. X 15. Photographs of irregular short-armed spec- 

 imens. 

 6. Astrorhiza vermiformis. X 5. Tyi>e figure. (After Goes.) 



Plate 7. 



Fig. 1. Rhabdammina abyssorum. X 15. Photograph of four armed specimen. 



2-5. Rhabdammina linearis. X 15. Photographs of specimens of the somewliat 

 slender irregular form . 



