8 BULLETIN 104, UNITED STATES NATIONAL MUSEUM. 



und Ordnungeu TMer-Reichs, 1880, p. 194, pi. 5, fig. 11.— H. B. Buady, 

 Rep. Voy. Challenger, Zoology, vol. 9, 1884, p. 231, pi. 19, figs. 1-4.— A. 

 Agassiz, Bull. Mu8. Gomp. Zool., vol. 15, 1888, p. 161, fig. 489.— Woodward, 

 The Observer, vol. 4, 1893, p. 78. — Goes, Kongl. Svensk. Vet. Akad. Handl., 

 vol. 25, No. 9, 1894, p. 12, pi. 1, figs. 1-3. — Rhumbler, Zeitsclir. Allgem. 

 Physiol., vol. 2, 1902, p. 204, fig. 46; Arch. Prot., vol. 3, 1903, p. 217, 

 fig. 36 (in text). — Cushman, Proc. Boston Soc. Nat. Hist., vol. 34, 1908, p. 

 22. — Heron-Allen and Earland, Journ. Quekett Micr. Club, sev. 2, vol. 10, 

 1909, p. 407, pi. 33, fig. 1. — ^Cushman, in Sumner, Osbui'n, and Cole, Bull. 

 Bureau U. S. Fisheries, vol. 31, pt. 2, 1911, p. 549. — Heron-Allex and 

 Eari-and, Trans. Zool. Soc. London, vol. 20, 1915, p. 607. 



Arenistella elegans (norncn nudum) Fisher and Defolin, Les Fonds de la Mer, 

 vol. 2, 1870, p. 26; 1872, vol. 2, p. 52. 



Ammodiscus lindahli Carpenter and Jeffreys, Proc. Hoy. Soc. Ijondon, 1870, 

 p. 159. 



Astrodiscus arcnaceus F. E. Schulze, in Jahresb. Komra. wiss. Untersuch. 

 Deutsch Meere, vol. 1, 1875, p. 113, pi. 2, fig. 10. 



flaechelina gigantea Bessels, .Tenaische Zeitsch. fiir nat., vol. 9, 1875, p. 265. 



Description. — Test free, compressed, irregularly stellate; com- 

 posed of a central disk from which horizontal arms radiate horizon- 

 tally around the peripheral region, variable in length and of irregular 

 form, usually long and slender, often irregularl}^ bifurcating at the 

 tips, 5-15 in number; wall thick, composed of mud with fine sand 

 grains, or in some cases entirely of rather coarse sand grains, interior 

 with a chininous lining, smooth, exteriorly roughened; ends of the 

 arms serving as apertures; wall grayish or yellowish, interior yel- 

 lowish brown. 



Diameter, including arms, up to 15 mm. 



Distribution. — From the available records this is a species of shal- 

 low waters and for the most part of temperate to cool regions. The 

 following are the Atlantic records: Coast of Bohuslan, Skager-Rack, 

 Sweden (Sandald, Loven); coast of Norway (Norman); off Heligo- 

 land, 21 fathoms (Schulze); off Dunbar (Balfour); west coast of 

 Scotland, 10-20 fathoms (Robertson, Ilerdman); Northumberland 

 and Durham (Brady) ; Torbay, Devon (Norman) ; coast of Connec- 

 ticut, 25 fathoms, and Maine (Bessels, Verrill); off Block Island; 

 south of Newport and south of Marthas Vineyard (Verrill); Anti- 

 cos ti and Gaspe Peninsula (Woodward) ; Vineyard Sound. 13 

 fathoms (Cushman), and off Cape Ann. 



Heron-Allen and Earland record a single specimen from the 

 Kerimba Archipelago off the eastern coast of Mrica. 



From the specimens I have been able to study, the material of the 

 test depends very greatly upon the character of the bottom. The 

 specimens from Gasp6 and from the sandy portion of Vineyard 

 Sound have the tests made of coarse quartz sand very largely, and 

 very little mud or fine material is used in their construction. 



