[27] ALBATROSS EXPLORATIONS. 529 
enumerate 34 species from between 2,000 and 3,000 fathoms, which is a 
much greater number than had previously been recorded from such 
depths in the North Atlantic. ; 
The species and varieties already described as new from the 1883 
collections are 76, as follows: Cephalopoda, 4; Gastropoda, 58; Soleno- 
concha, 4; Lamellibranchiata, 10. The total number of species of Mol- 
lusea added to the fauna of this region by the Fish Commission dredg- 
ings since 1880 is over 275. 
The different groups of Mollusca differ greatly in the relative propor- 
tion of deep and shallow water species, as shown by the following tables. 
Thus the deep-water Cephalopods are 23, against 4 shallow-water and 
surface species. The Gastropods exclusively deep water are 166, 
against 38 of shallow-water origin. The shallow-water Lamellibranchs, 
however, seem to have a much greater tendency to range into deep 
water, for of these there are but 68 deep-water species and varieties, as- 
sociated with 46 shallow-water ones. 
TUNICATA. 
On the upper part of the Gulf Stream slope, at the depths of about 65 
to 125 fathoms, in localities where the bottom is of compact sand and 
gravel, it is often well covered with various sponges, hydroids (Tubu- 
laria, Cladocarpus, &c.), and large, rough groups of a coarsely wrinkled 
ascidian, which appears to be identical with Cynthia partita Stimpson. 
This species occurs abundantly in shallow water on stones, piles, &c., 
from North Carolina to Vineyard Sound, often forming, in such situa- 
tions, large, irregular clusters. A few other species, not yet studied, 
also occur, though less commonly, on the hard bottoms in 100 to 125 
fathoms. At the northern stations, off Nova Scotia, where the bottom 
is often stony, many of the well-known northern forms occur, such as 
Boltenia Bolteni, Ascidia complanata, Cynthia pyriformis, &c. In the 
deeper waters, where the bottom is usually of soft mud and sand, or ooze, 
ascidians are not very common, though several undetermined species of 
Molgula and allied forms have been taken. One species of Molgula, 
which was taken in 1,608 fathoms, is about an inch in diameter, soft, 
flattened, and covered with a thick coat of foraminifera. 
The most interesting ascidian taken by us is a new species of the 
curious, long-stemmed genus, Culeolus, first discovered by the ‘ Chal- 
lenger.” It is peculiar to deep water, and a species very closely allied 
to our own was dredged by the “ Challenger” off the coast of Japan. I 
have named our species Culeolus Tanneri (figs. 144, 145, a. b.),* in honor 
of our accomplished commander. 


* Culeolus Tanneri Verrill, sp.nov. Stem long, slender, somewhat decreasing in size 
from the base to the summit. Body irregularly pear-shaped, the lower end tapering 
to a conical form, where it joins the stem, while the stem itself can be seen extending 
upward about 15 to 20™™ along the dorsal margin, where it forms, for that dis- 
tance, a rounded midrib terminating in a prominence in one specimen and at a de. 
H. Mis. 67 O-k 

