News of New Species - BIVALVIA

MYTILIDAE | PECTINIDAE | CARDIIDAE | VENERIDAE

MYTILIDAE

Modiolinae
Idas ghisotti Waren & Carrozza, 1990 (Bollettino Malacologico, Vol. 26, 1990, p. 19) - Length of holotype 11.2mm; shell slender, strongly convex, yellowish to olive brown. Its closes relative is I. simpsoni (Marshall), a larger species, which differs by being more inflated, by having a more distinctly concave ventral margin in adult specimens and by maintaining the posterior crenulation up to adult size. The type locality is the Tuscan Sea, off western central Italy, in deep water.

PECTINIDAE

Cyclopecten brundisiensis Smriglio & Mariottini, 1990 (Bollettino Malacologico, June, 1990, p.2) - Shell reaching at least 2.8mm, semicircular, almost quadrangular towards the umbones because of large ears. Left valve covered with a maximum of 19 radial costae completely covered with lamellae. Ears large, triangular and somewhat unequal, with up to four fine cords in the left valve covered with lamellae. Right valve rather concave, very compressed into the left valve and completely covered with concentric radial striae which extend to the ears. A short byssal sinus is present under the anterior ear of the valve. Internally, the species lacks reenforcement ribs or other type of sculpture. Type locality: the waters around Brindisi, Italy, in 21 meters of water.

Parvamussium conspectum Dijkstra & Kastoro, 1997 (Resultats des Campagnes MUSORSTOM 16(172): 258) ­ Shell up to 5 mm, fragile, semitransparent, valves equally convex, elongate, inequivalve, auricles unequal size. It is compared with Parvamusium sp.cf.texturatum of Dijkstra, which has shorter and more numerous (10 instead of 9) internal ribs. P. texturatum has a more orbicular shape, a weaker sculpture of concentric lamellae on the left valve, and more numerous internal ribs (15). Collected in eastern Indonesia in 100­250 meters. (Original description provided by Carol Marshall)

Semipallium marybellae Raines, 1996 (La Conchiglia, April-June, 1996, p. 20) - The species is similar to S. tigris, which is larger (up to 60mm) and has 9-11 fold-like ribs with some 95 secondary granulated radial riblets per valve. The new species measures up to 50.4mm, has only 9 costae and some 114 secondary, relatively smooth, riblets per valve. This species is more colorful, lacks the set pattern of S. tigris and the size of its byssal notch is half that of tigris. It inhabits the waters off the coast of Guam in 20-30 meters.

Serratovola pallula Dijkstra, 1998 (Molluscan Research 19(1): 28) - Shell up to 17 mm, inequivalve, equilateral, left valve somewhat concave, right valve convex, auricles near equal. Left valve dotted creamy-brown on brown; right valve uniform creamy-white. It is closest to S. gardineri, from the Maldive Islands, from which is differs by having a more concave left valve, with angular radial costae instead of the more acute costae of S. gardineri, and narrower interstices than the latter. The right valve of S. pallula is more convex and the ribs are more closely arranged. The new species is also compared to S. rubicunda, which has less angulate radial costae and larger interstices on the left valve. The left valve of S. rubicunda is slightly convex, that of S. pallula concave. The type locality is Hansa Bay, Papua New Guinea, in 60 meters. Material from northwestern and northern Australia is very similar to the type material and is under study. (Copy of the original description sent to the editor by Ms. Carole P. Marshall, whom we thank)

Veprichlamys versipellis Dijkstra & Kastoro, 1997 (Resultats des Campagnes MUSORSTOM 16(172): 270) ­ Shell fragile, up to 35 mm, somewhat obliquely ovate, compressed, equilateral, equivalve; auricles inequivalve. Adult specimens of V. versipellis have shagreen microsculpture on the anterior auricles, on the central part of the disc and near the ventral margin, while V. jousseaumei, a close species, has radial striae. V. perillustris from Australia has a more oblique shape and fewer (ca.20) radial ribs. It is also compared with V. kiwaensis, which also has fewer ribs and lacks shagreen microsculpture. It is found in the Banda and Arafura Sea, in 225­417 meters. (Original description provided by Carol Marshall)

CARDIIDAE

Acrosterigma fidele Vidal, 1992 (Apex, April, 1992, p.24) - Shell up to 75mm, subovoid, rather inequilateral, with the posterior part flaring out but truncated. The truncation gives the shell a subrectangular outline and shortens the posterior end, which is slightly depressed, giving it the appearance of a "wing." It is similar in general appearance to Acrosterigma elongatum (Bruguiere) but, according to the author, the "winged" character of fidele is more pronounced and the ribs are less numerous (31 in fidele and 40 on elongatum). In the medial section of the shell of fidele the ribs are extremely high and have a smooth flat top with finely crenulated edges. These edges overhang in such a way that the author compares them to an "overturned stem glass." The shape of the ribs and the winged character of the shell separates A. fidele from A. assimile, a species with which it has also been confused. According to the author, fidele appears in Springsteen and Leobrera's book, Shells of the Philippines, as Trachycardium (Vasticardium) elongatum (Brug.)

VENERIDAE

Granicorium citrinum Lamprell & Healy, 1999 (Molluscan Research 20(1): 76) - Shell up to 27.3 mm, suborbicular, equivalve, solid; lunule broadly heartshaped, strongly impressed; escutcheon wide, impressed. Antero-dorsal margin very short, sloping, angulate at anterior margin; postero-dorsal margin widely convex, steeply sloping. Sculpture of numerous, strong, widely spaced, concentric growth ridges present in the agglutinated sand in the extraperiostracal layer. Color externally yellow, internally chalky-white medially. It differs from G. indutum Hedley, 1906 by its consistently smaller adult size and less inflated shell, posterior margin relatively longer and straighter and umbones less prominent. The external color of G. citrinus is consistently yellow under the sand-colored extraperiostracal layer, while in G. indutum the external color is white. The new species inhabits northern Queensland, Australia, in 59 m, in sand.

Pitar (Pitarina) kathiewayae Lamprell & Kilburn, 1999 (Vita Marina 46(1-2): 33) - Shell up to 25 mm, ovate triagonal (hight/length, 0.68-0.94), more or less tumid (width/length, 0.58-0.73), inequilateral with high umbones situated 0.32-0.36 from anterior end; externally tan-brown (or brownish-orange), darker and more uniform on posterior third, more or less broken by irregular concentric bands of pale yellow; periostracum chalky white; internally white, usually with a few faint concentric violaceous lines and a mauve spot under the umbo. It most closely resembles P. hebraeus (Lamarck, 1818) and P. abbreviatus (Krauss, 1848), which are similar in shape and also occur in southeastern Africa. However, both of these species are larger (30 and 40 mm respectively), the anterior end of P. abbreviatus is shorter (0.26-0.34), and the average anterior end of P. hebraeus is longer (0.31-0.40). Moreover, the new species is more tumid, with a width/length ratio of 0.58-0.64 for P. hebraeus and 0.55-0.72 for P. abbreviatus. It inhabits the inner continental shelf of northern Zululand, South Africa, to littoral of northern Mozambique.

Pitar (Pitarina) medipictus Lamprell & Kilburn, 1999 (Vita Marina 46(1-2): 36) - Shell up to 32 mm, somewhat quadrate-ovate (hight/length 0.84-0.93), tumid (width/length 0.57-0.72), lunule lanceolate; sculptured with moderately fine concentric threads which are obsolete umbonally and medially; pallial sinus ascending, extending 0.35-0.44 of length of shell; dull off-white, median 2/3 usually with broad concentric or radial bands of brown, lunule not patterned, interior usually with a violaceous tinge. Its distinctive coloration readily separates this species from other ovate, inflated Pitar species. The species is endemic to the Agulhas Bank and Transkei shelf, from False Bay to off Port St. Johns.

Pitar (Pitarina) rectodorsalis Lamprell & Kilburn, 1999 (Vita Marina 46(1-2): 39) - Shell uniformly white, up to 34 mm, elongate-oval (height/length 0.83-0.85), posterior end slightly angular, postero-dorsal margin almost straight, valves inflated (width/length 0.60-0.69), umbones 0.30-0.36 from anterior end, posteriorly with slight, rounded umbonal ridge; lunule broadly cordate; pallial sinus ascending, 0.35-0.47 length of shell. The new species belongs to a group of elongate-ovate, inflated species. However, none of them posses similar traces of a posterior umbonal ridge. Additionally its uniformly white coloration separates it from most species. Pitar trevori Lamprell & Whitehead, 1990, P. japonicus Kuroda and Kawamoto, 1956, P. noguchii Habe, l958, and P. nipponicus Kuroda & Habe, 1971, also have uniformly white shells but lack both the umbonal ridge and the angulate posterior end of P. rectodorsalis. It inhabits the inner continental shelf of northern Zululand in clean, coarse sand in 40-85 m.

Tivela valae Lussi, 1996 (La Conchiglia, April-June, 1996, p. 40) -Shell up to 68.2mm; pallial line pointed conspicuously downward, sloping; pale brown with thin radial bands of yellowish-white. It is close to T. compressa but differs in having less convex ventral margin, larger shell, more compressed valves, and interior tinged with reddish-brown towards the dorsum. It occurs between northern Transkei and Zululand, and possibly East Africa.