NO. 1989. ASCIDIAN8 FROM NORTBEASTERN PACIFIC— RITTER. 495 



species to be examined, some of them would be found to possess 

 the peduncle. Assuming this interpretation of the seeming difference 

 between the two species as regards the peduncle to be correct, the 

 other differences between them seem to be slight. Michaelsen says 

 that there may be as many as nine coils in each stigmatic spiral in 

 A. glaciata. Four, or at most five, appear to be the maximum num- 

 ber in heringia. But of more importance, perhaps, the spirals in 

 glaciata are made up of a considerable number of stigmata placed end 

 to end, while in heringiaone or two stigmata constitute the entire spiral. 



A wide range of individual variation occurs in our species. From 

 some of the stations the specimens are all of the maximum size, or 

 nearly so, given in the diagnosis, and the large ones are nearly 

 devoid of sand on the test, and have rather thicker, more opaque 

 tests. Some of the other gatherings, on the other hand, are very 

 heavily coated with sand, and the test is very thin and transparent. 



Again, the position and course of the genital ducts differ consid- 

 erably, they being plainly visible in surface views in some specimens, 

 and quite hidden by the rectum in others. I fail, however, to find 

 any constancy and correlation of these variations that would warrant 

 the institution of more than one species. 



The collection contains several hundred specimens, all from the 

 southeastern Bering Sea mingled with St/ijela sahulifera in some jars: 



Albatross 3261, lat. 54° 42' 15'' N.; long. 164° 49' 15" W., 27 

 fathoms, bk. g. p., June 24, 1890. 



Albatross 3284, lat. 56° 16' 30" N.; long. 160° 53' W., 25 fathoms, 

 fne. g., June 29, 1890. 



Albatross 3287, lat. 56° 33' N.; long. 160° 14' W., 30 fathoms, 

 crs. bk. s., July 17, 1890. 



Albatross 3288, lat. 56° 26' 30" N.; long. 160° W., 15 fathoms, 

 bk. g., July 17, 1890. 



Albatross 3525, lat. 57° 21' N.; long. 170° 05' W., 29 fathoms, 

 bk. s. sh., August 4, 1893. 



Albatross 3543, lat. 56° 41' N.; long. 169° 39' W., 43 fathoms, 

 bk. s. sh., August 18, 1893, type locality. 



Albatross 3560, lat. 56° 40' N.; long. 169° 20' W., 43 fathoms, fne, 

 gy. s. bk. sp., September 3, 1893. 



Albatross 3496, lat. 56° 32' N.; long. 169° 45' W., 41 fathoms, 

 gy. s. St. gn. m., July 17, 1893. 



Type.— Cat. No. 5689, U.S.N.M. 



An interesting memorandum occurs on the reverse side of the label 

 for station 3287 to the eft'ect that one of the specimens was attached 

 to the back of a shrimp of the genus Crago. 



Note. — Since the above was written Huntsman (1911) has de- 

 scribed a species, A. septentrionalis, from the west coast of Canada. 

 This, too, appears to be nonpedunculate, and in other respects 

 somewhat more like glaciata than beringia. 



