580 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
position is indicated only by a few more closely grouped internal 
longitudinal vessels. This condition was found constant in a number 
of specimens examined. 
Transverse vessels of only three orders (arranged 1, 3, 2, 3, 1, etc.) 
are generally recognizable, though the large ones vary in size. The 
smallest generally cross without interrupting the stigmata. The 
number of internal longitudinal vessels on one side of the sac in a 
fairly large and typical example is about as follows : 
mdv. 1 (16) (4) 4 (12) 4 (3) 2 en. 
Number of transverse rows of stigmata between thirty and forty. 
Usually not more than four (sometimes in a few spaces six or seven) 
stigmata between internal longitudinal vessels where the latter are 
most widely separated, but between the median dorsal vessel and 
first internal longitudinal vessel six or eight, between the last vessel 
and endostyle eight or ten stigmata. These statements apply to the 
widest part of the sac of rather large individuals. 
Stomach with fewer longitudinal folds (20 to 25) than in P. fibrosa. 
Gastric caecum present. 
Intestinal loop rather wide and short. Margin of anus with a 
number of small but irregular lobes. 
Gonads and endocarps similar to those of P. fibrosa, but not very 
numerous in the specimens dissected. 
Exclusively a deep-water species which does not belong to the fauna 
of the New England region. The specimens examined are from the 
following stations, all at depths over 1400 fathoms: 
Station 2221 (N. lat. 39° 05' 30", W. long. 70° 44' 30", 1525 fathoms, gray 
ooze). 
Station 2038 (N. lat. 38° 30' 30", W. long. 69° 08' 25", 2033 fathoms, Glo- 
bigerina ooze). 
Station 2718 (N. lat. 38° 24', W. long. 71° 52', 1569 fathoms, brown ooze). 
Station 2714 (N. lat. 38° 22', W. long. 70° 17' 30", 1825 fathoms, browTi ooze), 
many specimens collected. 
Station 2229 (N. lat. 37° 38' 40", W. long. 73° 16' 30", 1420 fathoms, Glo- 
bigerina ooze). 
Genus Dendrodoa MacLeay, 1824. 
Distinguished from Tethyum by having the reproductive organs 
developed on the right side only. 
Folds of branchial sac generally more or less reduced. 
