ANATOMY AND SYSTEMATICS OF CARDIOLUCINA 



99 



erne 



Fig. 4 Cardiolucina australopilula anatomy. Right mantle and ctenidium 

 removed. Abbreviations aa - anterior adductor muscle, cme - cut mantle 

 edge, exa - exhalant aperture, ext - exhalant tube, fct - fused ctenidium 

 to mantle, ft - foot, let - left ctenidium, Ip - labial palps, me - mantle 

 edge, pa - posterior adductor muscle, ppr - posterior pedal retractor 

 muscle, r - rectum, vl - visceral lobe. 



Fig. 5 Semidiagrammatic transverse section through the posterior 

 exhalant area of C. australopilula showing the inverted exhalant tube 

 and the connection of the ctenidium to the mantle. Abbreviations: cm - 

 connection between mantle and ctenidium, ct - ctenidium, ea - exhalant 

 aperture, iet - inverted exhalant tube, lm - longitudinal muscle, me - 

 mantle edge, n - nerve. 



Fig. 6 Geographical distribution of Cardiolucina australopilula new 

 species. 



Cardiolucina civica (Yokoyama, 1927) 



Figs 7-9 



Cardium civica Yokoyama, 1927: 179. pi. 48, figs 3 & 4. 

 Dentilucina (Bellucina) hedleyi Prashad, 1932: 163-164, pi. 5, figs 



17& 18. 

 Bellucina civica (Yokoyama, 1927) - Kuroda, Habe & Oyama, 



1971:394, pi. 118 figs 17 & 18. 

 Lucina (Codakia) semperiana (Issel, 1869) - Melvill & Sykes, 



1898: pi. 3, fig. 1. 



TYPE MATERIAL. C. civica syntypes, University Museum, Tokyo, 

 CM 24913-24914, see Makiyama (1959); C. hedleyi holotype, I 

 individual 2 valves (ZMA). 



Type LOCALTIES. C. civica was described as a Pliocene fossil from 

 Nagaya and Kakuma in Kaga Province, Japan. C. hedleyi from the 

 Philippines, Sulu Archipelago, Siboga station 105 (6° 8'N, 121° 

 19'E), depth 275 m. 



Nomenclature. We have examined the holotype of C. hedleyi 

 from Indonesia, which is very similar to both Recent specimens of 

 C. civica from Japan and the fossils figured by Yokoyama (1927) and 

 consider them conspecific. 



SHELL DESCRIPTION. Shell solid, small, height to a maximum of 

 10.6 mm; subcircular, mean H/L 1.02, inflated, mean T/L 0.40, 

 tumidity to a maximum of 4.5 mm on a single valve. Shell slightly 

 extended anteriorly. There is a shallow posterior sulcus which has 

 concentric ribs. Lunule small and shallow. Anterodorsal area weakly 

 defined. Escutcheon slightly convex and finely ribbed. Exterior 

 sculpture of numerous (more than 30) fine, slightly rounded, radial 

 ribs with narrow interspaces. Radial ribs are crossed by many (more 

 than 25) conspicuous concentric lamellae, which are rounded in 

 profile and slightly recurved. Left valve with a single posterior 

 lateral, two cardinal teeth and a single posterior lateral; right valve 

 with a single posterior lateral, two cardinal teeth, the posterior 



