NO. 1989. A8CIDIANS FROM NORTHEASTERN PACIFIC— RITTER. 483 



table shows, two specimens of the most typical tuherculata (Nos. 2 

 and 4) possess the one 11, the other 9 lobes; and in general the varia- 

 tion in number of these is so great as to deprive them of much classifi- 

 catory value, at least so far as this species is concerned. The remark- 

 able reduction in the size of the branchial tentacles would at first 

 sight also seem sufficient to exclude these specimens from tuherculata. 

 But this again is one of those seemingly freakish variations that 

 occur in some organisms. The smallest individual of the lot, being 

 14 by 12 mm., had three tentacles situated about at the quadrants, 

 of good length and thickness, and no other, unless one or two at the 

 very earliest stage of development, for I have no doubt that in this 

 group new tentacles are added until a comparatively late period in 

 the lifetime of the individual animals. 



Mention ought also to be made of the fact that the stomach in 

 some, though not in all the specimens in this lot, resembles that of 

 D. aggregata more than it does that of the typical tuherculata. This 

 in conjunction with the lighter color and diminished tuberculation of 

 the test, has somewhat inclined me at times to assign these specimens 

 to aggregata. But the lobing of the anal rim and on the whole the 

 character of the digestive canal and the branchial sac have prevailed 

 in favor of considering them as representing a strongly marked race 

 or form of tuherculata. 



lAlhatross station 3505 (3 specimens), lat. 57° 09' N.; long. 168° 17' 

 W., 44 fathoms, fne. gy. s., July 28, 1893. 



Albatross station 2845 (1 specimen), lat. 54° 05' N.; long. 164° 09' 

 W., 42 fathoms, crs. bk. s., July 29, 1888. 



Albatross station 2849 (5 specimens), lat. 55° 16' N.; long. 160° 28' 

 W., 69 fathoms, gn. m., August 2, 1888. 



Albatross station 3213 (8 specimens), lat. 54° 10' N.; long. 162° 57' 

 30" W., 41 fathoms, bk. s. 



Albatross, 2 specimens. Otter Island, Bering Sea. 



Albatross station 3262 (a dozen specimens), lat. 54° 49' 30" N.; 

 long. 165° 02' W., 43 fathoms, bk. s. r., June 24, 1890. 



Albatross station 3504 (2 specimens), lat 56° 57' N.; long. 169° 27' 

 W., 34 fathoms, fne. gy. s. bk. sp., July 28, 1893. 



Albatross station 3216 (5 specimens), lat. 54° 20' 30" N.; long. 163° 

 37' W., 61 fathoms, bk. s. m., May 21, 1890. 



Albatross station 3536, lat. 57° 05' N.; long. 170° 35' W., 40 fath- 

 oms, gn. m. fne. s., August 8, 1893. 



Other than Albatross stations: About 75 specimens, mostly small 

 and in a compact mass, Unalaska, Alaska, washed up by the waves. 

 Turner collection; about 20 specimens, Constantino Bay, Amchitka 

 Island, 8 fathoms, Dall collection 1038; 2 specimens, Unalaska, Dall 

 collection; 3 clusters, Kyska Harbor, beach, Dall collection 1873; 

 2 specimens, no data. 



