Hulingsina Puri 1958

Hulingsina sondern Puri, 1958

Hemicytherideis aff. H. mayeri (Howe and Garrett).—Swain, 1955, p. 631, pl. 63: fig. 3.

Hulingsina sandersi Puri, 1958a, p. 173, pl. 2: figs. 10–14.

SHAPE.—Female carapace elongate-ovate in lateral view; highest anteromedially. Dorsal margin of right valve broadly convex, dorsal margin of left valve convex in anterior half and straight in posterior half. Ventral margin of both valves concave with greatest concavity in front of middle. Upper part of anterior margin tapered, remainder broadly rounded and extended below; anterior margin of left valve somewhat more broadly rounded than that of right. Posterior margin of right valve subtriangular, with posteroventral corner forming narrowly rounded extension; posterior margin of left valve obliquely rounded with no pronounced posteroventral extension. Carapace elongate-ovate in dorsal view with greatest width posteriorly from whence the sides converge gradually forward to narrowly rounded anterior and rapidly backward to bluntly pointed posterior.

ORNAMENTATION.—Exterior of valves covered with regularly arranged rows of papillae; elongate, papillate rows arranged, for the most part, subparallel to valve margins; subparallel arrangement of rows particularly noticeable anteriorly where four or five rows parallel anterior margin. Numerous (about 15) moderately well-developed denticles present along midanterior and anteroventral marginal rim. Raised marginal rim present along posterior margin of right valve. Distinct sulcus extending from near dorsal margin slightly in front of middle to about midheight, where it bifurcates. Valves rather heavily calcified.

SIZE.—Right valve of adult female: length 0.65 mm; height 0.27 mm. Left valve of adult female: length 0.66 mm; height 0.29 mm.

INNER LAMELLA.—Marginal area broad anteriorly, of moderate width elsewhere. Line of concrescence and inner margin separated; rather large scalloped anterior vestibule present as well as much smaller posteroventral one. Prominent, high and sharp, submarginal selvage present in right valve. Moderately broad, flat flange groove forming shelflike extension at posteroventral corner of right valve.

MARGINAL PORE CANALS.—Numerous throughout with greatest number anteriorly (25–32). Marginal pore canals occur as indentations of scalloped line of concrescence; long, simple, straight to slightly curved canals tend to occur in pairs.

HINGE.—Lophodont. Hinge of right valve consisting of very long, faintly crenulate tooth separated by long interterminal groove from a short, faintly crenulated posterior projection. Left valve hinge consisting of elongate anterior groove overlaid by a long, well-developed antislip bar; an elongate, slightly irregular interterminal bar, and a short, faintly crenulate posterior groove.

NORMAL PORES.—Moderately numerous, irregularly arranged, large sieve type.

MUSCLE SCARS.—Muscle scar pattern consisting of nearly vertical row of 3 closely spaced adductor scars with 4th above and slightly anterior to them; large V-shaped antennal scar present in front of and at about same height as top adductor scar; 2 lower, elongate, mandibular scars present.

EYE SPOTS.—Absent.

OVERLAP.—Left valve slightly larger than right and overlapping it around all margins except anteriorly; greatest overlap ventral.

SEXUAL DIMORPHISM.—Moderately pronounced. Female carapace shorter and higher than in male.

MATERIAL.—Three specimens collected in bottom samples from Redfish Bay and four from Copano Bay.