Van Name. — Simple Ascidians. 
Fig. 
137. 
Fig. 
138. 
Fig. 
139. 
Fig- 
140. 
Fig. 
141. 
PLATE 69. 
Bostrichobranchus pilularis (Verrill). Two large specimens free 
from incrusting sand and mud. Vinej^ard Sound. Nat. size. 
Teihyum rusticum (Linnaeus). Specimens from the Grand Banks. 
Nat. size. 
Caesira relortijormis (Verrill). Station 2699 (N. lat. 45° 04', W. 
long. 55° 23', 72 fathoms). Nat. size. 
Caesira retortiformis (Verrill). Eastport, Me. Nat. size. 
Tethyum partitum {Stimpson). Two groups of individuals. New- 
port, R. L Nat. size. 
