"Thaumatoconcha punctata, new species FIGURES 11 h, 12l, 13d, 56-58
HOLOTYPE—USNM 143861, adult female, some appendages on slide, others in alcohol; left valve in alcohol; right valve dry, gold-plated.
TYPE-LOCALITY—USNS Eltanin, Cruise 25, station 364, 56°17'S, 156°13'W to 56°19'S, 156’18°W, South Pacific, 3694 m.
PARATYPES —USNM 127289B, 1 adult female; USNM 127289C, 1 A-l female; USNM 127289D-E, 2 A-2 females; USNM 127289F, 1 juvenile, length 1.26 mm, height 1.14 mm (not opened). Paratypes from same sample as holotype.
ETYMOLOGY—The specific name is in reference to the punctate surface of the carapace (punctae were not observed on juveniles and poorly preserved adults).
DIAGNOSIS—Carapace surface with irregularly spaced shallow punctae and about 9 anteroventral ridges; straight anteroventral margin; length of female 2.22 to 2.24 mm; dorsal margin of 3rd joint of 1st antenna longer than dorsal margin of 4th joint; endopodite of mandible with 1 dorsal bristle on 1st joint and 2 on 2nd; rod-shaped organ with pointed tip.
DESCRIPTION OF ADULT FEMALE (male unknown)—Valves subround, height of anterior margin almost twice the height of posterior; straight anteroventral margin delimited by a dorsal and a ventral forward pointing very short truncated protuberance; anterodorsal margin broadly convex, merging with short gently curved dorsal margin at point about onethird greatest length; posterior margin gently rounded; forward and downward curving ventral margin joins posterior with slight angulation, curves upward approximately below subcentral adductor muscle-scar to join straight anteroventral margin below protuberance; dorsal outline subelliptical, greatest width slightly in front of midlength; end outline subelliptical, greatest width slightly below midheight.
Ornamentation: Surface with irregularly spaced shallow punctae and scattered hairs emerging from normal pores; anteroventral surface with 9 low ridges; proximal ridges wavy; practically no crossridges present; right closest to contact margin continues around entire valve; next 4 ridges extend dorsally, terminating about half way up anterior margin; proximal ridges progressively shorter than distal ridges.
Adductor muscle-scar: Scar subcentrally located, subovate, greatest diameter trending normal to hinge; scar consists of approximately 20 subequal pie-shaped segments more-or-less radially arranged.
Size: USNM 143861, length 2.22 mm, height 1.88 mm; USNM 127289B, length 2.24 mm, height 1.97 mm.
First and 2nd antenna, mandible, maxilla, 6th limb, 7th limb, furca, posterior of body: Similar to those on adult female of T. radiata.
Fifth limb: First exopodite joint of the holotype with 10 ventral bristles. (This joint on holotype of T. radiata bears only 7 ventral bristles, but the variability in the number of bristles on this joint was not determined for either T. radiata or T. punctata, so the observed difference in number of bristles for the 2 species may not be significant).
Rod-shaped organ: Elongate, 1-jointed or weakly 2-jointed, with broad proximal half; distal half strongly tapered with small process at tip.
Upper lip: With 4 small processes, otherwise similar to that of T. radiata.
DESCRIPTION OF FEMALE A-l INSTAR—Carapace similar in shape to that of adult but without punctations (only 1 specimen observed).
Size: USNM 127289C, length 1.85 mm, height 1.49 mm.
Furca: Similar to that on female A-l instar of T. radiata.
Rod-shaped organ: Elongate, 1-jointed, strongly tapering in distal half.
DESCRIPTION OF FEMALE A-2 INSTAR.—Carapace similar in shape to that of adult but without punctations (only 2 specimens observed).
Size: USNM 127289D, length 1.47 mm, height 1.33 mm; USNM 127289E, length 1.63 mm, height 1.42 mm.
Furca: Similar to that of female A-2 instar of T. radiata.
Rod-shaped organ: Similar to that on A-l instar but not quite so strongly tapered (observed only on USNM 127289D).
COMPARISONS—See Table 13." (Kornicker & Sohn 1976, p.78-83)
