Asteropterygion hulingsi (Kornicker 1975)

Asteropterygion hulingsi (Kornicker, 1975)

Asteropteron new species Kornicker.—Sohn, 1974:725, fig. le,f.

Asteropteron hulingsi Kornicker, 1975a:562, figs. 347–350.

HOLOTYPE.—USNM 128680, probably late instar.

TYPE-LOCALITY.—South Atlantic, east of Argentina, 40°11′S, 60°27′W, 44 m.

MATERIAL.—Right valve and appendages of holotype, USNM 128680.

DISTRIBUTION (Figure 131).—Collected only at type-locality.

DIAGNOSIS.—Carapace with distinct narrow peripheral ridge having 3 posterior processes; surface with shallow fossae containing elongate polygonal processes (Plate 116d) or reticulations (see Kornicker, 1975a, fig. 350d,e).

Second Antenna: 1st endopodial joint of female (probably late instar) without bristles (always?).

SUPPLEMENTARY DESCRIPTION OF HOLOTYPE.—Each valve with distinct, narrow, peripheral ridge having 3 posterior processes (Plates 115a, 116a,b); surface with shallow fossae containing elongate polygonal processes (Plates 115b, 116d); surface between fossae with irregular porous structures (Plate 115b) and oval areas with minute nodes (Plates 115b, 117b–d); bristles emerging from open pores with narrow lip scattered over valve surface (Plate 117a–d); these bristles with pore near base (Plate 117a) and with minute marginal papillae (Plate 117a,c); additional bristles emerging from either closed or open pores present along ventral and anterior margins (Plates 115a,e,f, 116a,b, 117e).

Infold: Infold present along anterior, ventral, and ventral half of posterior margins, being widest posterior to rostrum (Plate 115d); list of rostrum prominent and bearing long bristles (Plate 115d–f); additional bristles present on rostrum anterior to list; list along ventral infold with wide lamellar prolongation with anterior end just below inner end of incisur, and posterior end near posteroventral curvature of valve (Plates 115d–f, 118a,b); a few short bristles present between list and both ventral and anteroventral edges of valve (Plates 115e,f, 116a); ventral half of posterior margin with broad list without lamellar prolongation (Plate 118b); this list bearing bristles of various types—long tubular bristles (Plates 118c,d, 119d–f), short bristles with digitate tips (Plate 120e,f), clusters of short tubular bristles (Plate 120a–c), individual short tubes (Plate 120d); and long setose bristles present posterior to list (Plates 118e,f, 119a,b); a single row of bristles with divided tips present between broad list and posterior valve edge (Plates 118c,d, 119c).

Selvage: Selvage with wide lamellar prolongation present along anterior, ventral, and posteroventral margins (Plates 115d–f, 117e,f, 118a,b); edge of prolongation along ventral margin minutely digitate (Plate 117f); selvage divided at inner end of incisur; edge of prolongation at inner end of incisur with fringe (Plate 115f).

Central Adductor Muscle Attachments: Each valve in area of central adductor muscle attachments with numerous small bare spots forming clusters (Plates 115a,c, 116c). Each spot may represent the attachment of a muscle strand, and each cluster of spots may represent a single bundle of muscles.

First Antenna (Figure 133a), Mandible (Figure 133b,c), Maxilla (Figure 134a), Fifth Limb (Figure 134c), Sixth Limb (Figure 134b): The limbs were described by Kornicker (1975a:563–567). Note: The sensory bristle of the 5th joint of the 1st antenna bears filaments, not bristles as stated by Kornicker (1975a:563, lapsus); a reexamination of the maxilla revealed 2 exopodial bristles on the maxilla, not 3 as given by Kornicker (1975a:565).