File:American malacological bulletin (1988) (18152809752).jpg

Title: American malacological bulletin
Identifier: americanmal6719881990amer (find matches)
Year: 1983 (1980s)
Authors: American Malacological Union
Subjects: Mollusks; Mollusks
Publisher: (Hattiesburg, Miss. ?) : (American Malacological Union)
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

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KAAS AND VAN BELLE: CHITONS OF ARABIAN GULF 127
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100 /uvn Figs. 51-60. Acanthochitona woodwardi sp. nov. Fig. 51. Valve I, dorsal view, 3.33 mm wide. Fig. 52. Camera lucida sketch of valve IV, rostral view, 4.44 mm wide. Fig. 53. Valve IV, dorsal view, 4.44 mm wide. Fig. 54. Valve VIII, dorsal view, 3.38 mm wide. Fig. 55. Camera lucida sketch of valve VIII, lateral view, 1.95 mm. Fig. 56. Dorsal girdle spicules. Fig. 57. Small and large spicule from sutural tuft. Fig. 58. Ventral spicules. Fig. 59. Central and first lateral radula teeth. Fig. 60. Blade of major lateral tooth. (Figs. 56-60, scale bar = 100 ^m.) tral part, apophyses rounded, sharp, smooth, jugal sinus about 1/5 valve width, weakly concave, insertion plates rather short, slit formula 5/ 1/ 2 (figured specimen with only 4 slits in valve I), slits shallow, slit rays hardly or not indicated, teeth sharp, smooth to very finely striate, eaves solid. Girdle densely covered dorsally with small, straight to slightly bent, abrupty pointed, smooth spicules, ca. 60 x 10 urn (Fig. 56), sutural tufts relatively short, composed of straight, slender, sharply pointed, smooth spicules of different sizes, varying from 180 x 8 /*m to 400 x 30 /urn (Fig. 57). Ven- tral side of girdle paved with close set, radiating rows of sharp- ly pointed, smooth spicules, up to 100 x 20 /*m (Fig. 58). Marginal spicules similar to ventral ones. Central tooth of radula (Fig. 59) elongate tulip-shaped, with thin blade, first lateral tooth somewhat shorter, slender, slightly widening distally, anterolateral corner with sharply pointed outward lobe, no blade, major lateral with tricuspid head, denticles pointed, central one longer than others (Fig. 60). Gills merobranchial, abanal, 11 ctenidia per side. DISCUSSION: This species cannot be attributed to any known species in the Indian Ocean. Acanthochitona mahensis Winck- worth, 1927, from Mahe, India, and A. ashbyi Leloup, 1937, from the Indian Ocean (?), possibly a synonym of the former, differ in their greater size, more close packed, coarser granules, finely ribbed jugal areas, relatively wider tail valves with convex postmucronal slope, and longer, coarser, long- itudinally striate marginal girdle spicules. In A. curvisetosus Leloup, 1960, from the Red Sea, the granules are smaller and more rounded, the jugal areas relatively wider and orna- mented with ca. 15 longitudinal striations, and, contrary to those of A. woodwardi, the ventral girdle spicules are smaller than the dorsal ones. A. limbata Kaas, 1986, from Madagascar, differs in the form of the valves, the drop-shaped granules, the much broader jugal areas, and the form of the major lateral radula tooth. ETYMOLOGY: Woodward. This species is named after Mr. A. J. Genus Notoplax H. Adams, 1861 Type Species: Cryptoplax (Notoplax) speciosa H. Adams, 1861 (by monotypy). Subgenus Notoplax s.s. Notoplax (N.) arabica Kaas and Van Belle, sp. nov. Figs. 61-72 Schizochiton jousseaumei, Smythe, 1982: 84, fig. 18 (non Dupuis, 1917). Glayzer ef a/., 1984: 324. TYPE MATERIAL: HOLOTYPE, 11.4 x 5.9 mm, Kuwait Bay, Kuwait, on rocks and dead shells, intertidal, 14 Feb 1975, B. Glayzer leg., BMNH 1987031. PARATYPES: 2 spec, 9.9 x 5 mm and 8.3 x 3.9 mm, collected with holotype, BG 1195. —7 valves (disarticulated), collected with holotype, RMNH K5106. —1 spec, 11.0 x 6.0 mm (disarticulated), Fuwairat, Qatar, on rocks and dead coral, 0-1 m, June 1985, A. Wood- ward leg., KS. DISTRIBUTION: Kuwait, Qatar; intertidal. DIAGNOSIS: Animal small, 10-11 mm long, width about half length, rather flat, side slopes slightly convex, valves little beaked. Tegmentum uniformly light ochraceous, greyish or light orange, coarsely sculptured with large, strongly elevated, radially directed, elongate pustules, jugal areas wedge- shaped, raised, back rounded, neatly separated from the ad- jacent lateropleural areas by deep, wide grooves. Girdle finely spiculose, deeply encroaching between valves. Major lateral radula tooth tricuspid. DESCRIPTION: Head valve (Fig. 61) nearly semicircular, front slope weakly convex, anterior margin with five more or less distinct waves, posterior margin widely V-shaped, minutely notched in middle, no trace of radial ribs. Intermediate valves (Fig. 62) broadly triangular, front margin slightly concave at both sides of strong, forwardly produced, convex jugal part, hind margin weakly beaked, somewhat sinuose at sides, apices sharply pointed, lateral areas indiscernible. Tail valve (Figs. 63, 64) very small, transversely oval, mucro prominent, not elevated, slightly postmedian, posterior slope deeply concave.

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