20 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
ARAEOSOMA PARVIUNGULATUM Mortensen 
Araeosoma parviungulatum MortTENSEN, Vid. Medd. Dansk Naturh. Foren., 
vol. 98, p. 164, 1984; Monograph of the Echinoidea, vol. 2, p. 254, pl. 43; 
pl. 44; pl. 77, figs. 1-8, 1935. 
Locality.—Station 5645; in Buton Strait; North Island (NE.) 
bearing S. 10° W., 1.6 miles distant (lat. 5°29’06’’ S., long. 122°36’06’’ 
E.) ; 8377 meters; December 16, 1909. One specimen. 
Remarks.—A full description of this species, with figures, is given 
in the Monograph. It appears to be most nearly related to A. 
coriaceum, from which, however, it is easily distinguished, particu- 
larly by the much broader ambulacra and the much smaller hoofs 
of the oral primary spines. Also the pedicellariae are somewhat 
different. 
The intestinal canal was found to contain mainly bits of land 
plants. 
ARAEOSOMA OWSTONI var. NUDUM Mortensen 
PLATE 1, FIGURES 2, 3 
Araeosoma owstoni, var. nudum MortTENSEN, Vid. Medd. Dansk Naturh. Foren., 
vol. 98, p. 164, 1934; Monograph of the Echinoidea, vol. 2, p. 266, pl. 51; pl. 
52; pl. 77, figs. 9-12; pl. 80, figs. 1, 2, 1935. 
Localities Station 5135; in the vicinity of Jolo (Sulu); Jolo 
Light bearing S. 46° W., 11.9 miles distant (lat. 6°11’50’’ N., long. 
121°08’20”’ E.) ; 294 meters; bottom temperature 14.11° C.; fine coral 
sand; February 7, 1908. Two specimens. 
Station 53811; China Sea, in the vicinity of Hong Kong (lat. 
21°33’00’’ N., long. 116°15’00’" E.); 161 meters; coarse sand and 
shells; November 4, 1908. One specimen. 
Station 5314; China Sea, in the vicinity of Hong Kong (lat. 
21°41’00’"" N., long. 116°46’00’’ FE.) ; 223 meters; sand and broken 
shells; November 5, 1908. One specimen. 
Station 5446; eastern coast of Luzon; Atalaya Point, Batag Island, 
bearing S. 64° E., 5.3 miles distant (lat, 12°43’51’’ N., long. 124°59/18’” 
EK.) ; 540 meters; green mud; June 3, 1909. One specimen, the type. 
Remarks.—This form differs from typical A. owstoni only in having 
the aboral side much barer, its general appearance being thus con- 
spicuously different from the latter. It seems therefore desirable to 
distinguish it as a separate variety, in spite of the fact that there 
appear to be no other tangible differences. The fact that this form 
occurs also off the coasts of Annam indicates that it is the more 
southern representative of the typical A. owstoni of Japanese seas. 
One of the specimens from station 5135 is rather perplexing. It 
has more numerous tubercles (spines) on the aboral side than usual, 
and the pedicellariae show some peculiarity in the existence of a large 
