466 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Station 920 (off Martha's Vineyard, N. lat. 40° 13', W. long. 70° 41' 54", 
63 fathoms, green mud), many rather large specimens. 
Station 873 (off Martha's Vineyard, N. lat. 40° 02', W. long. 70° 57', 100 
fathoms, soft sticky mud). 
Station 876 (off Martha's Vineyard, N. lat. 39° 57', W. long. 70° 56', 120 
fathoms, soft sticky mud). 
Station 860 (Vineyard Sound, Cuttyhunk Light N. § W., 3 miles, 17^ fathoms, 
sand and mud). 
Station 788 (off Newport, R. I., 6 miles SSE. of Brenton's Reef Lightship, 
18 fathoms, fine sandy mud). 
Station 793 (off Newport, R. I., Point Judith WNW. | W., 6 miles, 19 fathoms, 
sand and broken shells). 
Off Block Island (specimens covered with very coarse sand). 
Noank, Conn. 
Fisher's Island Sound (off Sea Flower Reef, 7 fathoms). 
Long Island Sound (off New London, 6 to 9 fathoms). 
Huntington Bay, Long Island (collected by T. A. Tellkampf ; labeled Molgula 
pellucida as above noted). 
Fort Macon, North Carolina (collected by Dr. H. C. Yarrow; labeled 
Molgula pellucida as above noted, and differing considerably from the 
typical form). 
Traustedt gave this species the specific name manhattcnsis in the be- 
lief that it was identical with Caesira [Molgula] manhattcnsis (DeKay), 
1843. There is often considerable superficial resemblance between 
large specimens of this species and C. manhatlensis, and an error in 
Tellkampf's (1874) description of the latter has contributed to the 
confusion. Tellkampf stated that the branchial sac of Caesira 
manhattensis had no folds, from which one might suspect that his 
specimens were Bostrichobranchus and not Caesira, but neither the 
rest of his description, nor his figures, nor the localities of his speci- 
mens bear out this supposition, and Metcalf (1900) therefore con- 
cluded that the statement was an error. This conclusion the writer is 
able to confirm, having examined some of Tellkampf's specimens 
which are in the Yale Museum. They are typical C. manhattensis 
with the usual folds in the branchial sac. 
Genus Caesira Fleming, 1822. 
[= Molgula auct. plur.]. 
Branchial sac with five to seven longitudinal folds on each side 
which, if rudimentary, are at least indicated by a row of infundibula 
and by a group of closely placed internal longitudinal vessels (rarely 
by only one or two of the latter). 
