252 bulletin: museum of comparative zoology. 



Nephridia are peculiar in being remarkably extensive and in hav- 

 ing upwards of 20 or more efferent ducts on each side, nearly all of 

 which open on the dorsal aspect of the body (Text-fig. 15). 



Intestinal caeca voluminous, extending anteriorly as far as pos- 

 terior end of brain. 



Cerebral sense organs situated well in front of brain. 



Habitat. — (1) Pacific Grove and Monterey, California, in crevices 

 of rocks and among algae. Not very common. 



(2) Puget Sound and Alaska (Griffin, '98, p. 211). 



(3) I have found this species abundant at nearly all the collect- 

 ing stations of the Harriman Alaska Expedition from Victoria, B. C, 

 along the whole Pacific Coast of Alaska to Dutch Harbor, Unalaska 

 Island . 



(4) Saginaw Bay, Alaska. Low tide. Dr. W. 11. Jones, Dec, 

 1881. 



(5) " Portage Bay," Alaska. A single specimen, which ajrpeared 

 to have 16 pouches of accessory stylets, but I am not positive that 

 some of the stylets had not slipped out of place, and that there were 

 actually more than 12 pouches in life. 



(6) Security Bay, Alaska. Dr. W. H. Jones. The single speci- 

 men had 8 pouches of stylets, each containing one mature and one 

 immature stylet. 



(7) Unalaska Island. Collected by the Albatross. 



(8) Adakh Island (iVleutian Group). July, '93, Albatross. 



(9) Atka Island (Aleutian Group) . Albatross. 



The distribution of this species, so far as known at present, is 

 therefore from Monterey Bay, California, to Puget Sound to 

 British Columbia, and along the whole Pacific Coast of Alaska to 

 the Aleutian Islands. I have collected the species personally at 

 numerous localities along these 3000 miles of coast line. The region 

 of greatest al)undance, as indicated by my own ol)servations, is in 

 British Columbia and southern Alaska, where the Avorms live among 

 barnacles, mussels, algae, and other growths from low water well 

 up toward high-water mark, and are found on piles of whaiwes, 

 under stones and in crevices of rocks in almost all sorts of situations. 

 On cloudy days they are often seen crawling over stones between 

 tides, and are as hardy as they are restless. 



