Aequipecten heliacus (Dall, 1925)
DALL, W. H. 1925. Notes on the nomenclature of some of our East American species of Pecten with descriptions of new species. The Nautilus, 38: 112-120. [p. 119]
1925 Pecten (Aequipecten) heliacus Dall, 1925
Pecten heliacus Dall, holotype; M. Smith, 1937, East coast marine shells; descriptions of shore mollusks together with many living below tide mark, from Maine to Texas inclusive, especially Florida, plate 9, figures 5a, 5b.
|
«Shell of moderate size, more or less mottled and zoned in pinkish and crimson on a white surface, outline subcircular, very slightly oblique; ribs about 20, not dichotomous distally; narrow, almost keeled, with wider interspaces; valves equal, inequilateral, the ears subequal, the byssal notch wide and shallow, with a ctenolium of four teeth; the right valve somewhat paler than the other; the microscopic surface sculpture comprises a row of small pointed scales on top of the ribs, a smaller series on each side of each rib and 3 or 4 much finer prickly threads in the bottom of the channels between the ribs; the interior of the valve is more or less clouded with brownish purple, grooved to correspond to the external ribs, the ends of the flattish interspaces slightly excavated, the resilifer rather large; height, 38; length of valves, 40; of hinge line, 41; diameter, 11 mm. U. S. Nat. Mus. Cat. No. 333635.
Bahamas, fide W. F. Webb. This species has the general appearance of P. phrygium Dall, with which it had been placed in the collection, but the microscopic surface is quite different.» WILLIAM HEALEY DALL, 1925
|
«Records 2 specimens, inside a bait pot, Chesil Beach, Dorset, (54.57°N 02.47°W), 21 October 2014, Coll. Steve Trewhella.
Measurements Largest specimen 17.5mm.
Diagnosis Valves equally convex, disc circular, ears subequal, byssal notch marked with a ctenolium of 4 teeth. Sculpture of 20 rather acute radial ribs, each bounded by a row of fine spines and finer prickly threads in the interspaces. Left valve more strongly coloured than right valve, shades of orange brown.
Remarks Before the description of A. heliacus by Dall (1925) this species was thought to be the western Atlantic population of the European A. opercularis. Aequipecten heliacus is distributed from S. Carolina, Florida, Bahamas and into the Caribbean.»
HOLMES, A. M., P. G. OLIVER, S. TREWHELLA, R. HILL & D. T. G. QUIGLEY. 2015. Trans-atlantic rafting of inshore Mollusca on Macro-Litter: American molluscs on British and Irish shores, new records. Journal of Conchology, 42 (1): 41-50, figs. 1-8. [p. 45]
|
Aequipecten heliacus (Dall, 1925); A. M. Holmes et al., 2015, Trans-atlantic rafting of inshore Mollusca on Macro-Litter: American molluscs on British and Irish shores, new records, figure 4.
|
«Of the specimen shown on the right in figure 1, plate 10, Palmer said it ".. bears a resemblance to the holotype of P. heliacus Dall (1925b. p. 119-120) as figured in Maxwell Smith (1937, pl. 9, figs. 5a, 5b) ..." Pecten heliacus Dall is known only by the holotype, which was not figured until Smith reproduced photographs of it; his figure 5a shows the exterior of the left valve and 5b the interior of the right. Those figures, along with Dall's description, show that this valve of Carpenter's differs considerably from P. heliacus in being more convex, having a larger anterior auricle and a strongly produced anterior auricle (resulting in a much longer hinge margin), and in having wider ribs and different sculpture. Except for the longer posterior auricle and the less orbicular disk, this valve resembles P. acanthodes; it may be a geographical form of P. muscosus, being similar to some specimens of that species in the author's collection. Incidentally, P. heliacus must also be regarded a nomen dubium. It was described from a single specimen sent to Dall by the late shell dealer, Walter F. Webb; the locality Webb gave was "Bahamas," but he was quite unreliable in regard to data; furthermore, no specimen resembling the holotype has ever been reported from the western Atlantic.
In summation, it is the author's contention that Pecten squarrosus Carpenter is a nomen dubium; of the two syntypes, for neither of which a locality can he verified, one is definitely referable to the western Atlantic P. muscosus Wood and the other is a puzzle.» GRAU, G. 1959. Pectinidae of the eastern Pacific. Allan Hancock Pacific Expeditions, 23: viii, 308 p., pls. 1-57. University of Southern California Press. Los Angeles, California. [p. 157, 158]
|
Pecten (?var.) squarrosus Carpenter, 1865, syntypes; G. Grau, 1959, Pectinidae of the eastern Pacific, plate 10, figure 1.
|
«PECTEN HELIACUS Dall. Shell of moderate size, mottled and zoned with pink or crimson upon a white surface; ribs about twenty, narrow, nearly keeled, interspaces wider; valves equal, inequilateral, notch wide and shallow; right valve paler than left; pointed scales on top of ribs visible under a glass; interior clouded with brownish purple and grooved to match outside ribs. Length 40 mm.
PI. 9, Fig. 5 Southern Florida to West Indies.» SMITH, M. 1937. East coast marine shells; descriptions of shore mollusks together with many living below tide mark, from Maine to Texas inclusive, especially Florida. 308 p., pls. 1-74. Edwards Brothers, Inc., Ann Arbor, Michigan. [p. 34]
|
Pecten heliacus Dall, holotype; M. Smith, 1937, East coast marine shells; descriptions of shore mollusks together with many living below tide mark, from Maine to Texas inclusive, especially Florida, plate 9, figures 5a, 5b.
|