136 



D.G. REID AND C. OSORIO 



? Diplodonta phillippii Hupe, 1 854: 357-358, malacologia pi. 8, fig. 



5. 

 Felaniella inconspicua - Bernard, 1983: 30. 



Description. Shell 19 mm (to 32 mm, Soot-Ryen, 1959); orbicu- 

 lar, thin-shelled, only moderately inflated; sculpture of fine concentric 

 growth lines; the larger of two cardinal teeth in each valve bifid; 

 pallial line entire, not indented, adductor muscle scars almost equal; 

 colour white. 



Habitat. Dead valves dredged from 10-15 m depth, on bottoms 

 of gravel, coarse sand and cobbles; scarce. This species has been 

 recorded intertidally in sand, and living to depths of 36 m (Soot- 

 Ryen, 1959) and 65 m (Ramorino, 1968). 



RECORDS. Stations 7, 14. Elsewhere Tocopilla to Golfo Corcovado 

 (Soot-Ryen, 1959). Range: 22-49°S. 



Remarks. The four valves in the present material are more deli- 

 cate and less inflated than typical shells of F. inconspicua. In this 

 they correspond with the description of Diplodonta phillippii from 

 Isla Chiloe by Hupe (1854); although this was regarded only as a 

 form of D. inconspicua by Soot-Ryen (1959), the status of the two 

 taxa deserves further investigation. 



Family GALEOMMATIDAE 



Lasaea miliaris (Philippi, 1845) 



(Figure 7H, I) 



Kellia miliaris Philippi, 1845: 51. 



Lasaea miliaris - Soot-Ryen, 1959: 51. Dell, 1971: 174-175, pi. 1, 

 fig. 9, pi. 2, figs 3, 4. Castellanos, 1979: 136. 



Description. Shell to 2.8 mm; orbicular, inflated, umbos promi- 

 nent; sculpture of very fine, regular growth lines; colour pink to 

 purplish red. 



Habitat. In empty barnacles in barnacle zone of upper eulittoral, 

 on exposed and moderately exposed shores. At Isla Chiloe a similar 

 (possibly identical) form, identified as L. petitiana Recluz, was 

 abundant in the barnacle zone (Brattstrom, 1990). 



RECORDS. Stations 12, 14. Elsewhere Magellan Strait, Tierra del 

 Fuego, Falkland Is (Soot-Ryen, 1959; Dell, 1971). Range: 46-56°S. 



Remarks. Members of this genus are common components of 

 the crevice fauna on rocky shores throughout the world. The 

 taxonomy of this genus of minute bivalves was unsatisfactory 

 when based only on rather variable shell features (Dell, 1971). 

 However, it has now been thrown into further confusion by the 

 discovery that most of the 'species' are highly polyploid asexual 

 lineages, with nonplanktotrophic, brooded development (O Foighil 

 & Smith, 1995). The present material has been compared with 

 syntypes in NHM, but the specific name is used only in the sense 

 of a morphospecies. 



Family CARDITIDAE 



Carditella tegulata (Reeve, 1843) 



(Figure 7J) 



Cardita tegulata Reeve, 1843: sp. 48, pi. 9, fig. 48. Reeve, 1844: 



194. 

 Carditella tegulata - Lamy, 1922: 354-355, textfig. Carcelles & 



Williamson, 1951: 334. Dell, 1964: 194, textfig. 3, no. 8 (syn- 

 onymy). Osorio & Bahamonde, 1970: 197. Bernard, 1983: 34. 



Description. Shell to 7.5 mm; subtrigonal, solid; sculptured by 

 11-13 strong radial ribs, crossed by fine regular concentric ribs, 

 producing lamellate appearance on radials; margin coarsely 

 crenulated by radial ribs; small external ligament; colour whitish 

 with yellow brown periostracum. 



Habitat. Dredged from 10 m on bottom of cobbles, gravel and 

 coarse sand; uncommon. From 50 m at Valparaiso (Reeve, 1843). 



Records. Station 14 (5 specimens). Elsewhere Callao (Peru) to 

 Magellan Strait (Carcelles & Williamson, 1951). Range: 12-54°S. 



REMARKS. This species is closely similar to Carditella pallida 

 Smith, 1881. Smith (1881) distinguished his species by the 14—15 

 ribs and almost centrally placed umbos, and these characters are 

 confirmed by our examination of the two syntypes (NHM, type 

 locality Valparaiso). In comparison, the three syntypes of C. tegulata 

 (NHM, type locality Port Rosario, south Patagonia) have 11-12 

 coarser ribs and slightly more anterior umbones. However, these 

 differences are slight. The four specimens in the present material 

 resemble C. tegulata in sculpture, but the ribs are slightly less 

 pronounced, 1 1-13 in number, and the shell outline is closer to that 

 of C. pallida. Our specimens are therefore intermediate in form, as 

 well as in locality, between these two taxa and suggest possible 

 clinal variation between them. Dell (1964) emphasized the close 

 relationship of this pair of species; further investigation is desirable. 

 Care must be taken to distinguish this species from Carditopsis 

 flabellum, with which it occurs. Our familial assignment of both 

 these species follows Chavan (1969). The specimens figured by 

 Soot-Ryen (1959: pi. 1, fig. 11) and Marincovich (1973: fig. 9) are 

 not C. tegulata, but belong to the C. naviformis (Reeve, 1843) group, 

 with more oblong shells (see Dell, 1964). 



Family CONDYLOCARDIIDAE 



Carditopsis flabellum flabellum (Reeve, 1843) 

 (Figure 7K) 



Cardita flabellum Reeve, 1843: sp. 47, pi. 9, fig. 47. Reeve, 1844: 



194. 

 Carditopsis flabellum - Lamy, 1922: 360. Soot-Ryen, 1959: 40. 



Ramorino, 1968: 204-206, pi. 2, fig. 2, pi. 6, figs 2, 3. Bernard, 



1983: 35. 

 Carditopsis flabellum flabellum - Dell, 1964: 195, textfig. 3, nos 2, 



3 (synonymy). Osorio & Bahamonde, 1970: 197.Linse, 1997:59, 



pi. 2, figs 5-8, textfig. 12f. 



Description. Shell to 4.3 mm; subtrigonal, solid; sculptured by 

 13-14 strong rounded radial ribs, crossed by concentric, slightly 

 lamellose, growth lines; margin coarsely crenulated by radial ribs; 

 no external ligament, internal resilium between beaks; colour whit- 

 ish with yellow brown periostracum and black staining around 

 umbos. 



Habitat. Dredged from 10 m on bottom of cobbles, gravel and 

 coarse sand, and from 10-15 m on cobbles encrusted with calcareous 

 red algae; uncommon. Ramorino ( 1 968) found densities of up to 155 

 per m 2 in the Bahia de Valparaiso, on sandy mud at depths of 65-145 

 m. Reported from 25-135 m in the Magellan Strait (Linse, 1997). 



RECORDS. Stations 7, 14 (3 specimens). Elsewhere Callao (Peru) 

 to Magellan Strait (Soot-Ryen, 1959; Dell, 1964; Linse, 1997). 

 Range: 12-54°S. 



