584 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
a distinct species from Pyura aurantium. An examination of the 
internal anatomy would of course have proved the two species to be 
entirely distinct, since they belong to different families. 
The writer has so little confidence in the constancy and reliability 
of the characters by which species of this group have been distin- 
guished, that he considers it sufficient to treat the present form as a 
variety of D. aggregata Rathke, 1806, which is widely distributed in 
the northern regions of the Old World and has already been recorded 
from Greenland. D. kilkenthali Hartmeyer, (1899, 1903) from the 
Spitzbergen region has many characters in common with the Ameri- 
can specimens, though it has fewer internal longitudinal vessels. 
If it is not distinct from the American form, the name pulchella, 
whether regarded as a species or subspecies name, has priority. 
Dendrodoa kukenthali var. pedenicola Michaelsen (1912) from the 
Banks of Newfoundland seems unquestionably identical with the var. 
pulchella here described, and probably also the Casco Bay and New- 
foundland specimens of D. aggregata recorded by Hartmeyer (1903, 
pp. 239, 240) are to be referred to this variety. The conclusions 
drawn by Hartmeyer that Ascidia carnea Agassiz, 1850, and Cynthia 
placenta Packard, 1867, are identical with Dendrodoa aggregata Rathke 
are wholly disproved by an examination of the specimens in the 
Peabody Museum. 
Distribution of the variety pidchella: Banks of Newfoundland and 
coasts of Nova Scotia to Eastport, Me., and probably Casco Bay. 
10 to 40 fathoms. Shelly or stony bottom, preferred. Type locality, 
Eastport, Me. 
Localities of specimens examined : 
Banks of New'foundland. 
Station 2444 (N. lat. 45° 59', W. long. 49° 45' 30", 39 fathoms, white sand, 
broken shells), one small specimen. 
Station 2445 (N. lat. 46° 09' 30", W. long. 49° 48' 30", 39 fathoms, broken 
shells), three large specimens. 
Station 2446 (N. lat. 46° 20', W. long. 49° 52', 40 fathoms, broken shells), 
one poor specimen apparently of this species. 
Station 2449 (N. lat. 46° 37', W. long. 49° 50' 30", 39 fathoms, broken shells), 
four large specimens. 
Stations 53, 54 (Bedford Basin, north of Halifax, N. S., 35 fathoms, mud), 
several small and medium-sized specimens. 
Station 59 (Halifax, N.S., Outer Harbor, \ mile SSW. Rock Head bouy, 25 
fathoms, gravel), several large specimens. 
