"HOLOTYPE— USNM 128956, 1 gravid female, some appendages on slides, others in alcohol; right valve in alcohol, left valve gold-plated dry.
TYPE-LOCALITY—Vema Cruise 16, station V- 16-37.
ETYMOLOGY—The specific name is derived from the Greek, "pholion" [= small hole] in reference to the small pits covering the surface of the carapace.
PARATYPES—USNM 128957, 1 gravid female, not dissected; USNM 128958, 4 juveniles, not dissected. Paratypes from same sample as holotype.
ADDITIONAL SPECIMENS—USNM 137457, 1 adult female (not dissected) from same sample as holotype; USNM 137045, 1 gravid female from Vema Cruise 15, station V-15-93; USNM 137052, 1 juvenile from Vema Cruise 16, station V-16-39; USNM 137053, 1 adult 2 without eggs from Vema Cruise 15, station V-15-110.
DIAGNOSIS OF FEMALE—Carapace with small punctations, which on some specimens decrease in size anteriorly; horizontal ridges faint, and both midribs absent on anterior part of shell; carapace length 1.87 to 1.93 mm. Appendages similar to those on A. dithrix.
DESCRIPTION OF FEMALE—Carapace strongly calcified and with numerous small punctations which on some specimens decrease in size anteriorly on carapace; horizontal ridges faint, and both midridges absent on anterior part of shell; single hairs scattered over valve surface.
Infold and selvage: Same as on A. dithrix.
Size: USNM 128956, length 1.92 mm, height 1.24 mm; USNM 128957, length 1.93 mm, height 1.32 mm; USNM 137045, length 1.93 mm, height 1.30 mm; USNM 137053, length 1.87 mm, height 1.26 mm.
Appendages: Same as those on A. dithrix with following exceptions: ventral margins of 1st joint of 1st antenna with few clusters of short spines; bristles on exopodite of mandible of some specimens without long spines.
Eyes: Same as those on A. dithrix.
Eggs: USNM 128956 with 4 eggs in marsupium; USNM 137045 with 17 eggs.
REMARKS CONCERNING SPECIMEN FROM V-15-110—An adult female from this station has a rounded tip on the frontal organ and long proximal spines on both bristles on the exopodite of the mandible, in other respects the specimen conforms with A. pholion.
COMPARISONS—This new species is closely related to A. dithrix and A. chilensis. The carapace of A. pholion differs from both species in having smaller punctae on the carapace and, on some specimens, the size of the punctae are much smaller on the anterior half of the shell than they are on the posterior half. Specimens of A. pholion in the collection are more strongly calcified than those of both A. dithrix and A. chilensis, but this could vary. The 2 midridges are not present on the anterior part of the shell of A. pholion but are present on the other two species. The size of the carapace of A. pholion is intermediate between those of A. chilensis and A. dithrix. Anarthron pholion also differs from A. dithrix in having a few spines along the ventral margin of the 1st joint of the 1st antenna.
DISTRIBUTION—This species was collected only in the Subantarctic region east of Argentina (50°17'S to 54°10'S) at depths of 82 to 284 m." (Kornicker 1975, p.361-362)
