MOLLUSCA OF SOUTHERN CHILE 



119 



mediates appear to connect these two forms and therefore we have 

 not retained the subspecific distinction. Nacella deaurata (Gmelin, 

 1 79 1 ) was recorded, probably erroneously, from 'Laguna San Rafael' 

 by Brattstrom & Johanssen (1983; see above); this southern species 

 is a more elongate oval shape, with nodular radial ribs. Nacella 

 magellanica was reportedly one of the principal food species of the 

 Fuegian Indians (Osorio et ai, 1979), but was not found in the 

 middens on Isla Traiguen. 



Family LEPETIDAE 



loihia coppingeri (Smith, 1881) 

 (Figure 7A) 



Tectum (Pilidium) coppingeri E.A. Smith, 1881: 35, pi. 4, figs 12, 



12a. 

 Lepeta coppingeri - Castellanos & Landoni, 1988: 32, pi. 1, fig. 6, 



pi. 3, fig. 9. Linse, 1997: 27. 

 Iothia coppingeri - Moskalev, 1977: 62-64, figs 5, 6. Dell, 1990: 



105-106, figs 185, 186 (synonymy). 



DESCRIPTION. Shell to 4.2 by 3.1 mm; delicate, translucent, apex 

 close to anterior end; sculptured by numerous fine, scaly, radial 

 riblets, but sculpture sometimes obsolete; colour usually white, 

 sometimes orange brown, or dark brown with white rays. 



Habitat. 10-15 m depth, on substrates of cobbles encrusted with 

 calcareous red algae, and of cobbles and shell debris on silt. It has 

 been recorded from depths of 5-1 108 m (Dell, 1990; Linse, 1997). 



Records. Stations 7, 14, 25. Elsewhere Tierra del Fuego and 

 Magellan Strait, and more widely in Falkland Is and circum-Antarc- 

 tic (Dell, 1990). According to Dell (1990) the northern limits are not 

 well defined, so that our records may be the northernmost for this 

 species. Range: 46-78°S. 



Family LOTTIIDAE 



Scurria ceciliana (d'Orbigny, 1841) 

 (Figure 2H, I) 



Patella ceciliana d'Orbigny, 1841: 482, pi. 81, figs 4-6. 



Patelloida ceciliana -Dell, 1971: 199-200 (synonymy). 



Collisella ceciliana - Marincovich, 1973: 19-20, fig. 33 (syn- 

 onymy). Castellanos & Landoni, 1988: 2, pi. 3, figs 10, 11, pi. 4, 

 fig. 2. 



Scurria ceciliana - Espoz, Guzman & Castilla, 1995: 191-197, fig. 

 3d. 



Description. Shell to 20 by 18 mm, height 7 mm; low-conical, 

 apex at one third of shell length from anterior margin; sculptured by 

 12-15 rounded ribs that crenulate the margin; colour white, with fine 

 black or brown tessellation between ribs, merging into radial lines at 

 margin; interior white or greenish, exterior pattern shows through at 

 margin, spatula irregular, dark brown or of several axial brown 

 streaks. 



Habitat. On surface of rocks with green algae in barnacle zone, in 

 upper eulittoral on moderately sheltered shores. Dell (1971) and 

 Brattstrom (1990) recorded this species mainly from the mid and 

 upper littoral, but also lower on the shore. In northern Chile, 

 Marincovich (1973) found it in the middle and lower intertidal. 



Records. Stations 1, 8. Elsewhere Pucusana (Peru) to Tierra del 

 Fuego and Magellan Strait (Dell, 1 97 1 ; Marincovich, 1 973). Owing 



to taxonomic confusion in this group (see below), the geographical 

 distribution is uncertain. Provisional range: 12-54°S. 



Remarks. According to Lindberg (1988), the lottiid limpets of 

 Chile are all assigned to the genus Scurria. These comprise a poorly 

 known complex of species, much in need of critical revision (contrast 

 the treatments by Dell, 1971; Marincovich, 1973; Ramirez, 1974; 

 Hockey et ai, 1987; Espoz et al., 1995). The present form is 

 identified as S. ceciliana, since it corresponds with d'Orbigny's 

 (1841) description and figure (the types are lost), and resembles 

 specimens from the type locality in the Falkland Islands (NHM). This 

 species is one of several which, when strongly eroded at the apex, can 

 show a striking mimetic resemblance to a large barnacle. This is 

 achieved by the exposure of the dark brown and streaked shell layers 

 beneath the myostracum, which produces a pattern resembling the 

 tergal and scutal plates of a barnacle (Hockey etal., 1987). Erosion of 

 the shell is facilitated by the lichen Thelidium litorale (Espoz et al., 

 1995). In the present samples of S. ceciliana only a few specimens 

 show this erosion pattern, and in these the mimicry is less striking 

 than in Scurria species from further north on the Chilean coast. 



Scurria parasitica (d'Orbigny, 1841) 



(Figure 2F, G) 



Patella parasitica d'Orbigny, 1841: 481, pi. 81, figs 1-3. 

 Scurria parasitica - Marincovich, 1973: 21-22, fig. 37 (synonymy). 



Description. Shell to 1 5 by 1 3 mm, height 8 mm; high conical to 

 tall cap-shaped, apex at one third of shell length from anterior 

 margin; outline oval to almost round; plane of base often curved to 

 fit shell substrate; radial sculpture weak, of fine striae, often eroded 

 away or obsolete, occasionally developing weak radial ribs; colour 

 variable, often varying in concentric zones on the same shell, 

 usually with 13-20 broad radial white stripes, with brown or black 

 marbled or lineated sectors between; may be uniformly blackish 

 brown, or flecked with white; interior white with irregular brown 

 spatula, external pattern showing through at margin. 



Habitat. On shells of large molluscs (Nacella, Acanthina,Mytilus) 

 in eulittoral, on sheltered and moderately exposed shores; also on 

 shell material on eroding edge of large midden. In central and 

 northern Chile the species reaches larger size (29 mm) and inhabits 

 large chitons, Fissurella and other Scurria species (d'Orbigny, 

 1841; Marincovich, 1973). 



RECORDS. Stations 1, 7, 10, 12, 14. Elsewhere Callao (Peru) 

 (NHM), Chincha Is (Peru) to Talcahuano (Marincovich, 1973), 

 extended southwards by the present records. Range: 12^46°S. 



Family FISSURELLIDAE 



Puncturella (Puncturella) conica (d'Orbigny, 1841) 

 (Figure 7B) 



Rimula conica d'Orbigny, 1841: 471, pi. 78, figs 10, 11. 



Puncturella conica - Powell, 1951: 86-87 (synonymy). Powell, 

 1960: 127. Dell 1971: 178-179, pi. 5, figs 10, 11, 14, 15 (syn- 

 onymy). Arnaud, 1972: 113-114. Castellanos & Landoni, 1988: 

 20, pi. 3, fig. 1 



Puncturella cognata (Gould, 1852) -Powell, 1951: 86. Linse, 1997: 

 27. 



Puncturella spirigeraThide, 1912-Powell, 1960: 127. Dell, 1990: 

 76, figs 125, 127. 



