The Ascidians of Point Barrow, Alaska, Part 1 
Suborder Phlebobranchia (Enterogona) 
Donald P. Abbott 1 
During the years 1948 to 1951 sizeable col- 
lections of ascidians were made by workers at 
the Arctic Research Laboratory, Point Barrow, 
Alaska. Most of the specimens were dredged 
during the summers of 1948 to 1950 under the 
supervision of Professor G. E. MacGinitie of 
the California Institute of Technology, in the 
course of an extensive survey of the distribu- 
tion and ecology of the marine invertebrates of 
Point Barrow. 2 This material was forwarded to 
me for study through the kindness of Professor 
MacGinitie and of Drs. Paul Illg and Fenner 
A. Chace, Jr., of the Smithsonian Institution, 
U. S. National Museum. Additional small col- 
lections of ascidians were made in 1950-1951 
by Dr. Ira L. Wiggins and Mr. James Bohlke 
of Stanford University; these have been made 
available to me by Miss Margaret Storey of the 
Natural History Museum, Stanford University. 
It is a pleasure to express my thanks to those 
named above. 
A general account of the environment and 
marine invertebrate fauna of Point Barrow is 
now available (MacGinitie, 1955). This gives 
complete locations and descriptions of dredging 
stations 1-62 (MacGinitie, 1955: 60-85, fig. 
1), and includes some information on the dis- 
tribution and ecology of the ascidians (pp. ISO- 
183). The ascidian names used by MacGinitie 
are based on determinations made by myself. 
McGinitie’s locality records are more compre- 
hensive than those included here, for he has 
listed some records resulting from field identi- 
fications (using determined comparison speci- 
mens) of material which was not preserved for 
later study. In the present systematic account I 
1 Hopkins Marine Station of Stanford University, 
Pacific Grove, California. Manuscript received October 
12,1959. 
2 Supported by funds from the Office of Naval Re- 
search, Contract and Task Order no. N6-onr 24316, 
Project no. NR 162 911. 
have cited only specimens which I have exam- 
ined personally. 
The collections contained 27 ascidians be- 
longing to the suborder Phlebobranchia, rep- 
resenting 3 species: Ascidia callosa , Chelyosoma 
macleayanum, and C. inae quale. The first 2 
species are familiar arctic forms; while well 
known, much remains to be learned of their 
variability. C. inaequale is previously known 
only from 10 specimens, plus three very dubious 
records from deep water off southern California 
and Panama (Van Name, 1945: 209). Collect- 
ing data on the material examined are listed in 
Table 1. 
In the following section the references listed 
are limited to a few earlier works which have 
made important contributions or which con- 
tain good descriptions or extensive bibliog- 
raphies on the species concerned. The descrip- 
tions given are intended to supplement, not 
duplicate, the existing accounts cited for each 
species. 
order ENTEROGONA 
suborder PHLEBOBRANCHIA 
family ASCIDIIDAE 
Ascidia callosa Stimpson, 1852 
Ascidia adhaerens Ritter, 1901, pp. 227-230, 
pi. 27, figs. 1-5. 
A. ( Ascidiopsis ) columbiana Arnbiick, 1934, 
pp. 53-55, text figs. 13-14. 
A. callosa Hartmeyer, 1924, pp. 41-53; Huus, 
1930, pp. 1-11, figs. 1-6; Arnback, 1934, 
pp. 49-52, pi. 4, 6, figs. 19-26, 43-44, 
text fig. 12; Van Name, 1945, pp. 178-180, 
pi. 4, fig. 5, text figs. 92-94. 
Ascidiopsis columbiana Huntsman, 1912, pp. 
110-113, pk 10, fig. 5, pi. 14, figs. 5, 7, 8. 
DESCRIPTION: The following notes supple- 
ment the description given in Van Name 
137 
