﻿426 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 102 



Distribution. — From Kodiak Island, Alaska, to San Quintfn, 

 Baja California. There are records from temperate and tropical 

 waters of both hemispheres (see under Remarks) . 



Habitat. — This, the dominant sipunculid of the intertidal zone, 

 has adapted itself to a variety of habitats from midtide horizon to 

 110 fathoms. It is probably most abundant on the lower half of the 

 intertidal zone and just below low tide. Beds of mussels (Mytilus 

 calif ornianus) so characteristic of the California coast afford ideal 

 conditions. It is found also under rocks lying on or in fine sandy 

 to muddy bottoms of tide pools, and in some conditions in crevices 

 of rocks, preferred by Dendrostomum j^yroides. The root masses of 

 surfgrass (Phyllospadi.r) if not clogged with drifting sand, and hold- 

 fasts of kelps afford protection for small specimens. Mr. Ricketts 

 found them also in the fenestrated base of a colony of the hydrocoral 

 Allopora californica. Professor MacGinitie found them common in 

 the mud of Humboldt Bay, which evidently afforded favorable con- 

 ditions, as the specimens are all of large size. 



At Orcas Island, Wash., Dr. Richard Snyder found a medium- 

 sized specimen in association with the annelid Aphrodite. The sipun- 

 culid was in the space betw^een the elytra and the dorsal mat of inter- 

 woven chaetal threads and must have entered when very tiny. 



Specimens examined.— From Baja California: 



Boca de la Playa, near Ensenada, Jan. 21, 1932, E. F. Ricketts, 5 specimens. 

 San Quintin, April 1949, Patrick W. Wells, 5 specimens. 



From California: 



La Jolla, 1899, F. H. Robinson, 1 specimen. 



San Clemente Island, June 26, 1896, H. B. Torrey, 2 specimens. 



San Pedro Point, Sept. 1, 1895, 1 specimen. 



Point Firmin, U. S. National Museum collection, 1 specimen. 



Santa Monica, March 1889, J. J. Rivers, 4 specimens. 



Santa Barbara, under wharf, summer of 1948, Patrick H. Wells, 5 specimens. 



Santa Rosa Island (Beechers Bay), mussel bed, Aug. 10, 1948, D. M. Wootton, 



34 specimens. 

 Santa Cruz Island (Frys Harbor), uuissel beds, Aug. 12, 1948, D. M. Wootton, 



10 specimens. 

 Point Conception, July 14, 1916, C. L. Hubbs, 2 specimens. 

 Albatross station 4496, 2.1 miles southeast of Santa Cruz, 10 fathoms, fine gray 



sand, rocks. May 19, 1904, Albatross, 33 specimens. 

 Albatross station 4551, 4.5 miles northwest of Point Pinos, 56-46 fathoms, rocks, 



coarse sand, June 7, 1904, Albatross, 7 specimens. 

 Monterey Bay, channel off Moss Landing, 110 fathoms, Nov. 28, 1927, 1 specimen. 

 Monterey Bay, about 50 feet, from colony of Allopora californica, Feb. 10, 1927, 



E. F. Ricketts, 18 specimens. 

 Monterey Bay, intertidal, from Point Pinos to Carmel Bay, granite shore, many 



specimens. 

 Pillar Point, San Mateo County, March 12, 1911, W. F. Thompson, 10 specimens. 

 Tomales Bay, Nov. 23, 1947, P. J. Menzies, 1 specimen. 



