ANATOMY AND SYSTEMATICS OF CARDIOLUCINA 



105 



Caas -*5-a* ' 



Comparison with other species. This is a small distinctive 

 species with an exterior ornament similar to C. eucosmia and C. 

 siquijorensis. It is smaller, more circular in shape and lacks the 

 deeply-excavated lunule of C. eucosmia. C. siquijorensis has fewer 

 and broader radial ribs, a shallower lunule and a different dentition. 



Habitat. Shallow water to 240 m. 



Distribution. Western Australia (Fig. 15). 



Material examined. AUSTRALIA: Western Australia, W. of 



Rottnest Island, 110m (WAM 262-94); Point Peron Peninsula, 

 Shark Bay (WAM 257-94, 258-94, 259-94, 260-94,); Carnarvon 

 (WAM); N. of Homestead Point, Dirk Hartog Island (WAM 250- 

 94); Ningaloo Reef, N.W. Cape (WAM); Mangrove Bay beach, 

 N.W. Cape (WAM); Yardie Creek to Tantibiddi, N.W. Cape (WAM 

 wet material); N.W. of Port Hedland, 1 12m (AM C.309462); N.W. 

 Shelf, W. of Roebuck Bay, 238m (AM C.309464); Broome (ANSP 

 233737); Northern Territory, N. of Cobourg Peninsula, 55m 

 (AM); 200km N. of Melville Island, 215m (AM). 



Fig. 13 Geographical distribution of Cardiolucina eucosmia (Dall). 



Western Australia, Prince Frederick Harbour (WAM); Cape Leveque 

 (AM); Port Hedland (AM); Direction Island, off Onslow (AM 

 C.69334). 



Cardiolucina pisiformis (Thiele, 1930) 



Figs 14-15 



Phacoides (Parvilucina) pisiformis Thiele, 1930: 592. 



Phacoides (Parvilucina) pisiformis Thiele - Ponder, 1 978: 439, pi. 2 



figs 3 & 9. 

 Bellucina pisiformis (Thiele) - Slack-Smith, 1990: 135. 



HOLOTYPE. Museum fur Naturkunde, Berlin. Reg. no. 67726. L= 

 3 mm, H= 2.9 mm (details from Ponder, 1978). 



TYPE LOCALITY. 5 km N.W. of Denham, Shark Bay, Western 

 Australia, 3 m. 



SHELL DESCRIPTION. Shell very small, to a maximum height of 4.4 

 mm, outline circular, H/L mean 0.97; inflated, T/L mean 0.42, 

 tumidity of single valve to 2.0 mm. Inequilateral, slightly extended 

 anteriorly. Shallow posterior sulcus with concentric lamellae. Lunule 

 heart-shaped, slightly excavated, smooth. Anterodorsal area indis- 

 tinct. Posterodorsal area with concentric lamellae. Exterior sculpture 

 of 13-17 low, flattened, radial ribs with broad interspaces. Ribs 

 broader and more rounded towards anterior of shell. About 20 thin, 

 concentric lamellae project slightly above radial ribs. Sculpture 

 distinctly fenestrate in appearance. Hinge plate strong. Left valve 

 with single posterior lateral, two cardinal teeth, the posterior of these 

 large and robust, the anterior small. Single anterior lateral tooth. 

 Right valve with a single, strong, posterior lateral tooth, two cardi- 

 nals, the anterior large and the posterior very small and a single 

 anterior lateral. Ligament extends from beak to posterior lateral 

 tooth. Inner margin with about 13 coarse crenulations, which are 

 sometimes bifurcate with occasional small denticles in the 

 interspaces. Small, rounded denticles around anterior and posterior 

 dorsal margins. Anterior adductor muscle scar elongate, slightly 

 buttressed with only the ventral tip detached from the pallial line. 

 Posterior adductor muscle scar rounded. Pallial line continuous. 

 Shell white. 



Juvenile shells (Fig. 14 e) are more extended both anteriorly and 

 posteriorly, with a prominent convex anterodorsal area. 



Cardiolucina quadrata (Prashad, 1932) 

 Figs 16-17 



Dentilucina (Bellucina) hedleyi var. quadrata Prashad, 1932: 164, 

 pi. 5 figs 19 & 20. 



Type material. Holotype, one individual two valves, L=10.5 

 mm, H=10.5 mm. Also 4 paratype valves. (ZMA). 



Type locality. Siboga Expedition station 212 (5° 54.5'S, 120° 

 19.2'E), west of Salayar, Sulawesi, Indonesia, 462 m. 



SHELL DESCRIPTION. Shell solid, small, height to 12.9 mm, 

 subcircular, H/L mean 0.97, moderately inflated, mean T/L 0.38, 

 tumidity to a maximum of 5.3 mm on a single valve. Shell 

 inequilateral, extended anteriorly. Shallow posterior sulcus with 

 concentric lamellae; umbones prominent. Lunule extremely small 

 and shallow. Anterodorsal area heart-shaped, slightly convex with 

 fine concentric lamellae. Escutcheon lanceolate, with fine concen- 

 tric lamellae and a few radial ribs. Exterior sculpture of about 25 

 fine, closely spaced, radial ribs which are rounded in profile. Radial 

 ribs crossed by 25-30 low, broad, concentric lamellae, the intersec- 

 tion giving a finely beaded appearance. Hinge plate thick. Left valve 

 with an single posterior lateral tooth, two cardinal teeth, the anterior 

 of which is hooked and sits on a rounded buttress, and a single 

 anterior lateral tooth. Right valve with single posterior lateral, two 

 cardinal teeth with the posterior larger and a single anterior lateral 

 tooth. Ligament elongate extending from beak to two thirds of 

 distance to the posterior lateral tooth. Inner margin with about 25 

 crenulations, some of those to the posterior bifurcating. Shallow 

 sinus on posterior margin. Anterior adductor muscle scar elongate, 

 not buttressed, slightly detached at the ventral tip from the pallial 

 line. Posterior adductor muscle scar ovate. Pallial line continuous. 

 Shell colour white. 



Comparison with other species. Although this species name 

 was first introduced by Prashad ( 1 932) as a variety of Dentilucina 

 (Bellucina) hedleyi (= C. civica) it is clearly distinct. In many 

 characters, such as hinge teeth, it resembles C. australopilula, but 

 differs in shape and external sculpture, the latter having a fenes- 

 trate ornament compared with the finely beaded sculpture of C. 

 quadrata. 



Habitat. A deeper water species from muds at 230-1280 metres. 



