MOLLUSCA OF SOUTHERN CHILE 



127 



striae; aperture becoming somewhat thickened and lirate within in 

 largest specimens; colour dark bluish or purplish grey, aperture 

 purple. 



HABITAT. Common in rock pools in Mytilus zone, among holdfasts, 

 under stones and in shell gravel, on moderately exposed shores; also 

 under stones on silt, in sheltered tidal pool, just sublittoral. Previous 

 authors have recorded this species mainly from the lower eulittoral 

 and shallow subtidal, but occasionally from depths of up to 16 m 

 (Powell, 1951) or 40 m (Strebel, 1905a). It was found in a survey of 

 Macrocystis holdfasts in the Beagle Channel (Ojeda & Santelices, 

 1984). ' 



Records. Stations 5, 12, 14. Elsewhere I. Chiloe to Magellan 

 Strait and Tierra del Fuego (Strebel, 1 905b); Dell ( 1 97 1 ) records this 

 species only as far north as 49°S. Range: 43-55°S. 



Remarks. The development of the axial ribs is variable, some 

 examples being almost smooth, and both Strebel ( 1 905b) and Powell 

 ( 1 95 1 ) distinguished three species on the basis of shell characters. A 

 critical revision is required to confirm whether these are but forms of 

 a single species (Dell, 1971). 



Pareuthria powelli Cernohorsky, 1 977 

 (Figure 4D) 



Pareuthria rosea (Hombron & Jacquinot, 1854) - Powell, 1951: 

 133. Dell, 1971: 206-207 (synonymy) (junior primary homonym 

 of Fusus roseus Anton, 1838). 



Pareuthria scalaris (Watson, 1882) - Powell, 1951: 134 (syn- 

 onymy). Cernohorsky, 1977: 109 (synonymy) (junior primary 

 homonym of Fusus scalaris Lamarck, 1816). 



Pareuthria powelli Cernohorsky, 1977: 109, fig. 5 (synonymy). 



Description. Shell to 17 mm; elongate fusiform; sculptured with 

 rounded axial ribs (9-12 on last whorl), crossed by fine spiral ribs 

 (about 21 on last whorl) becoming finer and sometimes obsolete 

 towards suture; apertural lip thin or (in thick-shelled specimens) 

 slightly thickened and indistinctly denticulate within ; colour pinkish 

 purple or white. 



Habitat. Under stones on silt, in sheltered tidal pool, just 

 sublittoral; dredged from 7-9 and 10-15 m, on bottom of silt with 

 pebbles and shells, and on cobbles with encrusting calcareous algae. 

 Recorded from depths of up to 201 m (Powell, 1951). 



RECORDS. Stations 7, 14, 22, 25. Elsewhere from 47°48'S in 

 northwest Patagonia (Watson, 1886: 203), 49°S to Magellan Strait 

 (Dell, 1971) and Tierra del Fuego (Strebel, 1905b), so that the 

 present records are the most northerly. Range: 46-55°S. 



Remarks. The synonymy above follows Cernohorsky (1977). If 

 this is correct, this is a variable species in shell thickness, promi- 

 nence of sculpture, elongation of spire and colour, but a critical 

 reappraisal based on more material is necessary. Although some- 

 what eroded, the protoconch of the present specimens appears to be 

 only about two-thirds of the size of that of shells from the area 

 between the Falkland Islands and Patagonia. 



Glypteuthria meridionalis (Smith, 1881) 



(Figure 7E) 



Euthria meridionalis E.A. Smith, 18 

 Euthria (Glypteuthria) meridionalis - 

 21, fig 11, lla-d. 



1:29-30, pi. 4, fig. 6. 

 Strebel, 1905b: 627-629, pi. 



Glypteuthria meridionalis -Powell, 1951: 138. Dell, 1972: 36, fig. 

 10 (synonymy). Castellanos, 1992: 19, pi. 1, fig. 11. 



Description. Shell 6.2 mm (to 9 mm, Smith, 1881); narrowly 

 fusiform; sculptured with rounded axial ribs (14 on last whorl), 

 crossed by spiral grooves (about 13 on last whorl); apertural lip 

 slightly thickened and smooth within; colour whitish. 



Habitat. Single specimen dredged from 10 m, on bottom of 

 cobbles, gravel and shells. To 38 m (Powell, 1951). 



RECORDS. Station 14. Elsewhere recorded only to the south from 

 Portland Bay, St Andrew's Sound to Magellan Strait (Smith, 1881) 

 and Tierra del Fuego (Strebel, 1905b). Range: 46-55°S. 



Family NASSARIIDAE 



Nassarius gayii (Kiener, 1834) 

 (Figure 4E) 



Buccinum gayii Kiener, 1834: 71-72, pi. 21, fig. 79. 



Nassarius gayi - Marincovich, 1973: 37, fig. 80. Castellanos, 1992: 

 23, pi. 2, fig. 18. 



Nassarius gayii - Cernohorsky, 1975: 141-143, figs 44-49 (syn- 

 onymy). Cernohorsky, 1984: 34 (synonymy). 



Description. Shell to 14 mm; broadly fusiform; sculptured with 

 axial ribs, becoming obsolete at end of last whorl, crossed by flat 

 spiral ribs (10-11 on last whorl), forming low nodules at their 

 intersections; apertural lip thickened and lirate within; colour pale 

 brown with dark brown spiral ribs, aperture white with brown 

 margin. 



Habitat. Among Mytilus holdfasts and on shell gravel, in rock 

 pools in low eulittoral on moderately exposed shores; more com- 

 monly dredged from 6-15 m, on bottoms of cobbles encrusted with 

 calcareous algae, on gravel, and on silt with shell fragments. At 

 Iquique in northern Chile Marincovich (1973) recorded this species 

 from the middle and lower intertidal, on the undersides of rocks in 

 gravel. At Isla Chiloe Brattstrom (1990) found it commonly in the 

 lower eulittoral zone. 



RECORDS. Stations 1, 5, 7, 11, 12, 14. Elsewhere I. Lobos de 

 Afuera (Peru) (Marincovich, 1973) to Puerto Rosario and Bahia 

 Tom (50°S, Smith, 1881) and Magellan Strait (Dall, 1909). The 

 southern limit is unclear; the species was common around 46°S in 

 the present study, Smith (1881) recorded seven immature specimens 

 (as 'Nassa taeniolata Philippi, 1845') from 50°S, and Dall (1909) 

 stated that the species ranged to the Magellan Strait (54°S), yet Dell 

 (1971) did not record it in extensive collections between 42 and 

 55°S. Range: 7-54°S. 



Family VOLUTIDAE 



Adelomelon ancilla (Lightfoot, 1786) 



(Figure 4F, M) 



Voluta ancilla Lightfoot, 1786: 137. 



Adelomelon ancilla - Powell, 1951: 160-163. Castellanos & 



Landoni, 1992: 8, pi. 1, fig. 1. Poppe & Goto, 1992: 21, 109-1 10, 



pi. 35 (in part). 

 Adelomelon (Adelomelon) ancilla - Clench & Turner, 1964: 152— 



154, pis 82, 83, 92-94 (synonymy, radula). Weaver & duPont, 





