ANATOMY AND SYSTEMATICS OF CARDIOLUCINA 



103 



Linga (Bellucina) crassilirata (Tate, 1887) - Lamprell & White- 

 head, 1992: pi. 21 figs 128a & b. 



Holotype. South Australian Museum No. D. 12957. L = 8.5 mm, 

 H = 8.3 mm, T = 7.0 mm. 



Type LOCALITY. Streaky Bay, near Ceduna, South Australia. 



Shell description. Shell small, solid, height to 8.4 mm, outline 

 circular, H/L mean 0.98; shell moderately inflated with T/L mean 

 0.41, tumidity of a single valve to a maximum of 3.4 mm. Shell 

 slightly inequilateral, extended anteriorly. Shallow sulcus poster- 

 iorly, with concentric lamellae. Lunule small and shallow. Escutcheon 

 slightly convex, with fine concentric ribs. Exterior sculpture of more 

 than 30 fine concentric lamellae, clustered in groups of 4-6 with 

 broader interspaces between the clusters. Radial sculpture of many 

 fine ribs visible in the interspaces of the concentric ribs. Hinge plate 

 narrow; left valve with single posterior lateral, two cardinal teeth and 

 single anterior lateral. Right valve with a single posterior and 

 anterior laterals and two cardinal teeth, posterior cardinal larger than 

 anterior cardinal tooth. Ligament long, extending from beaks to 

 posterior lateral tooth. Inner margin with around 60 fine crenulations. 

 Anterior adductor muscle scar, elongate, not buttressed, with ventral 

 quarter detached from pallial line. Posterior adductor muscle scar 

 ovate and not buttressed. Pallial line discontinuous. Shell greyish 

 white. 



Comparison with other species. See C. civica. 



Habitat. Shallow subtidal to 70m. 



Distribution. South Australia, Victoria and Tasmania (Fig. 1 1 ). 



Material examined. AUSTRALIA: Victoria, BMNH 

 1906.9.19.70-2; Western Port (BMNH 1963200); BMNH 

 1911.12.19.11-12; Western Port (WAM); Western Port (AM 

 C.303440); Western Port, 15-18m (AM C.309469); Port Fairy, 

 beach (ANSP 135488); New South Wales, Between Eagle and 

 Crawfish Rock (AM); South Australia, Spencers Gulf (BMNH 

 1893.12.12.352-54); Hardwicke Bay (AM C. 13463); Neptune I., 

 70m (AM); South Australia (AM C.6677); Tasmania, Geography 

 Strait, 27m (AM C.38 180). 



Cardiolucina eucosmia (Dall, 1901) 

 Figs 12-13 



Lucina pisum Reeve, 1850 (in part): pi. 11 fig. 66a (non Lucina 



pisum Sowerby,1836: 341). 

 Phacoides (Bellucina) eucosmia Dall, 1 90 1 : 806 (replacement name 



for L. pisum Reeve). 

 Phacoides eucosmia Dall. - Hedley, 1909: 426, pi. 37 fig 16. 



Type material. Lectotype here selected BMNH 1963 194/1 (Figs 

 12a-d). Paralectotypes BMNH 1963194/2-3; 1845.825.210-212; 

 1963552 (this is C. semperiana see p. 107) 



TYPE LOCALITY. Restricted to Port Essington, Northern Territory, 

 Australia (modified from Reeve, 1850). 



Nomenclature. Many authors, for example Fischer (1871), Lamy 

 (1920), Chavan (1969), Britton (1972), Bretsky (1976) and Oliver 

 (1992) have considered Lucina semperiana Issel, 1869 a senior 

 synonym of P. eucosmia. However, Lucina pisum Reeve, for which 

 Dall gave the replacement name Phacoides eucosmia, is based on a 

 syntype series composed of two distinct species. For the reasons 

 given above in the generic section, we consider the specimens from 

 Port Essington to conform most closely with Reeve's description 



and concept of Lucina pisum and one of these has been selected as a 

 lectotype. The other syntypes from Singapore, now become 

 paralectotypes and we consider these to be the eastern Indian Ocean 

 form of C. semperiana (Fig. 21 a & b). 



Shell description. Shell solid, small, height to 7.8 mm, 

 subcircular in outline, slightly extended in an anterolateral direction, 

 H/L mean 1 .05; inflated, T/L mean 0.49, tumidity to a maximum of 

 3.8 mm on a single valve. Posteriorly, there is deep sulcus extending 

 from hinge to ventral margin. The sulcus and the posterior portion of 

 the shell has fine concentric ribbing with no radial ribs. The lunule 

 is 'U'-shaped and deeply incised to the ventral edge of the hinge 

 plate. Anterodorsal area is slightly convex, ovate in outline with fine 

 concentric sculpture. Posterior dorsal area broadly lanceolate in 

 outline, convex, with fine concentric ribbing. Exterior sculpture of 

 about 12 broad, radial ribs with rounded profile, somewhat flattened 

 on upper surface. Ribs narrower towards umbos. Interspaces between 

 ribs deep, narrower than ribs. Radial ribs crossed by 13-14 thin, 

 low, concentric lamellae which project slightly above radial ribs. 

 The intersection of concentric and radial sculpture gives a distinctive 

 fenestrate ornament. Hinge plate thick. Left valve has a single, 

 strong lateral tooth posteriorly, two thin, cardinal teeth, the posterior 

 tooth much larger than the anterior. Cardinal teeth are denticulate 

 (see Fig. 1 2d). A single anterior lateral lies close to perimeter of the 

 lunule. Right valve has a single posterior lateral, a large single 

 cardinal tooth and a single anterior lateral. Both valves have small 

 denticles around the dorsal margin of valve. Ligament elongate, 

 extending from beak to posterior lateral tooth. Inner shell margin 

 thickened, with 12 coarse crenulations. Small sinus on posterior 

 lateral margin corresponding to position of sulcus. Anterior adduc- 

 tor muscle scar elongate, sitting on a shallow buttress with the only 

 the ventral tip detached from the pallial line. Posterior adductor scar 

 ovate on a shallow buttress. Pallial line is thin and continuous. Shell 

 colour creamy white. 



Juvenile shells (Figs 12 e & f) are less inflated and more extended 

 anteriorly. The lunule is widely opened in younger stages. Denticles 

 are absent on the dorsal inner margins. Radial ribs begin narrow and 

 broaden ventrally between each concentric rib. Radial ribs are 

 visible on interior of shells. 



Comparison with other species. Although C. pisiformis, C. 

 siquijorensis and C. australopilula have a similar fenestrate orna- 

 ment, C. eucosmia can be easily distinguished from all other species 

 by the deeply incised lunule. 



HABITAT. Low intertidal to 100 m in fine sand and mud. Hedley 

 ( 1 909) reports dredging the species in the Gulf of Carpentaria from 

 about 10 m in soft black mud, where it was abundant. 



Distribution. Northern Australia (Fig. 13). 



Material examined. AUSTRALIA: Northern Territory and 

 Queensland, BMNH 1963490, 1963236, 1910.9.28.77-8; W. of 

 Cape York, 8m (BMNH 1887.2.9.2776-7); Gulf of Carpentaria 

 (NMW 1955.158); Sweers I. (AM C.75249, 78223); Forsyth I. (AM 

 C.14892); Horsey River mouth, 9m (AM C.15152), Karumba (AM 

 C. 14963); Mapoon (AM C. 14281); off Bountiful Islands (AM); 

 Gulf of Carpentaria (AM C.100498); mid-Gulf of Carpentaria, 66m 

 (AM); off Albany River (AM); Karumba Point (AM 1909); Albany 

 Passage, 8-25m (AM C. 36172); Port Essington (BMNH; off Point 

 Charles, Darwin, 27-37 m (AM C.309468); Van Diemen's Inlet 

 (NMW 1955.158);Van Diemen's Inlet (AM C. 15273); lOOmilesN. 

 of Croker Island, Arafura Sea, 124m (AM C.309454); 150 km N. of 

 Coburg Peninsula, 108m (AM); Dinah Beach, Darwin (AM); Cro- 

 codile Research Station, Manningrida, Arnhem Land (AM); 



