64 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



Tkolosina bulla Rhumbler, Nachr. Kongl. Gee. Wiss. Gottingen, 1895, p. 82. — 

 KiAER, Norske Nordhavs Expedition, No. 25, 1899, p. 4. — Rhumbler, 

 Arch. Prot., vol. 3, 1903, p. 227, fig. 52 (in text).— Cushman, Bull. 71, 

 U. S. Nat. Mus., pt. 1, 1910, p. 49, fig. 55 (in text\— Pearcey, Trans. Roy. 

 Soc. Edinburgh, vol. 49, 1914, p. 1002. 



Pseudoplacopsilma bulla Eimer and Fickert, Zeitschr. Wiss. Zool., vol. 65, 

 1899, p. 672. 



Descrijytion. — -Test adherent, liemispherical or at least strongly 

 convex, base flattened or irregular to conform to the surface to which 

 it is attached ; on a narrow base the test is usually somewhat elongate 

 in the direction of the length of the attachment; chamber single, 

 usually undivided; wall thick, composed of sand grains or fine 

 amorphous material with much calcareous cement, outer surface 

 somewhat uneven, interior fairly smooth aperture simple, circular 

 elliptical or crescentiform, one or two, at either end near the base; 

 color grayish white. 



Diameter, not usually exceeding 1 mm. 



Distribution. — Two Atlantic stations are given in the OMUenger 

 Report Porcupine station 19, in 1,366 fathoms, west of the North of 

 Ireland, and from a Challenger station, in 1,900 fathoms, east of 

 Buenos Aires. Goes records it from the Skagerack hi 160 to 530 

 meters attached to Rhahdammina and from the Koster Islands at 

 18-140 meters attached to Fucus. Under this name, however. 

 Goes includes, or at least his figures include Ammolagena clavata, 

 so these records are somewhat obscure without recourse to original 

 material. Kiacr records it from the subarctic region. The species 

 occurs more abundantly on the Pacific coast of America, especially 

 off the Central American and Mexican coasts (Goes, Cushman), 

 and it is known from off the Pacific coast of Chile (Brady) ; Malay 

 Archipelago (Millett), oft' Japan (Cushman), and from the Antarctic 

 Pearcey) . 



When attached to a more or less regular surface of different color 

 like the cylindrical reddish tubes of Rluibdammina this becomes a 

 conspicuous object by its difference in color and changing the contour 

 line of the surface to which it is attached. When attached to other 

 light-colored bases, however, it is not easily seen. Tliere is a tendency 

 to division in some of the chambers. 



In the Albatross material I have examined it has occurred at 20 

 stations between the Grand Banks and Cape Hatteras, depths ranging 

 from 82 to 2,620 fathoms, bottom temperatures from 36.4° to 40.6° F. 

 Most of these are attached to the Rhabdammina but are never in any 

 considerable numbers at any station. 



