128 



1970: 102-103, fig. 20a-c, n, pi. 42A-C (synonymy). Osorio, 

 Atria & Mann, 1979: 19-20, fig. 19. 



Description. Shell to 186 mm (Clench & Turner, 1964); large, 

 fusiform, with long narrow aperture; sculpture usually smooth but 

 for very fine growth lines, but apical whorls may bear fine spiral 

 striae and longitudinal ribs; apertural lip smooth, only slightly 

 thickened, columella with 2-A sharp folds; colour cream with sparse 

 longitudinal zigzag brown lines, dark brown when covered by 

 periostracum, interior pale orange. 



HABITAT. 0-172 m (Powell, 1951), on sand bottoms to 310 m 

 (Poppe & Goto, 1992). The single dead shell in the present material 

 was dredged from 10 m on a gravel bottom. 



RECORDS. Station 14. Elsewhere Magellan Strait to Falkland Is- 

 lands and southern Brasil (Clench & Turner, 1964), I. Chiloe (M.G. 

 Harasewych, pers. comm.). Range: 42-54°S. 



Remarks. This species is represented in the present collection by 

 a single dead shell, a small juvenile of 18 mm (Fig. 4F), clearly 

 assigned to the Volutidae by the large protoconch (with evidence of 

 a pointed calcarella, see Clench & Turner, 1964: pi. 93) 5.2 mm in 

 diameter. Identification to species has been based on the relatively 

 narrow first whorl of the teleoconch (indicating a tall narrow spire) 

 and on the teleoconch sculpture of spiral striae and slight axial folds. 

 Many specimens of A. ancilla are smooth at the apex, but this 

 sculptured form was described by Strebel ( 1 906) as Voluta martensi, 

 subsequently synonymized by Clench & Turner (1964). An adult 

 shell of A. ancilla from the Falkland Islands is illustrated in Figure 

 4M. The taxonomy of this complex of large Magellanic volutes 

 remains confused. Powell (1951) pointed out the similarity of the 

 shells of A. ancilla and A. magellanica (Gmelin, 1791) and regarded 

 them as extremes of a single variable species. However, Clench & 

 Turner (1964) figured two very different radulae, and on this basis 

 transferred the latter to the new genus Odontocymbiola, distinct at 

 subfamilial level. Characters of the shell were not entirely diagnos- 

 tic, but that of O, magellanica was said to be broader and more solid, 

 and the protoconch apparently larger. This treatment was followed 

 by Weaver & duPont (1970). However, in the most recent mono- 

 graph of the family, Poppe & Goto (1992: 21, 109-110) have 

 rejected the evidence of the radular differences, and on the basis of 

 shell characters have synonymized these two, together with A. 

 paradoxa (Lahille, 1895). Clearly, additional anatomical informa- 

 tion is required to resolve this problem. The egg capsules are 

 attached to hard substrates; one illustrated by Strebel (1906: pi. 10, 

 fig. 52) is domed, 53 mm in diameter and contains seven embryonic 

 shells up to 14 mm in length; capsule and embryos have also been 

 figured by Carcelles (1944: pi. 3, figs 35-38). 



Family TRITONIIDAE 



Tritonia challengeriana Bergh, 1884 



Tritonia challengeriana Bergh, 1884: 45^17, pi. 11, figs 16-19, pi. 

 12, figs 1-8 (anatomy, radula). Schrodl, 1996: 35, pi. 6, fig. 39 

 (synonymy). 



Description. Animal up to 35 mm; oral veil with finger-like 

 processes; rhinophores with basal sheaths; body approximately 



D.G. REID AND C. OSORIO 



quadrilateral in cross section, along each lateral angle the mantle 

 forms a row of 15-21 branched pallial gills; colour white. 



Habitat. Among and beneath stones in pools in lowest eulittoral, 

 at top of red algal zone, on moderately sheltered shore. Recorded 

 from depths up to 18 m by Schrodl (1996), and dredged from 315 m 

 by the Challenger Expedition (Bergh, 1884). Members of this 

 family mostly feed on alcyonarians (Thompson & Brown, 1984). 



RECORDS. Station 14. Elsewhere I. Chiloe to Magellan Strait 

 (Schrodl, 1996). Range: 42-54°S. 



Family FLABELLINIDAE 



Flabellina falklandica (Eliot, 1907) 



Coryphellafalklandica Eliot, 1907: 354, pi. 28, fig. 7 (radula). 

 Flabellina falklandica - Schrodl, 1996: 37, pi. 7, fig. 44 (syn- 

 onymy). 



Description. Animal up to 10 mm (to 40 mm, Schrodl, 1996); 

 rhinophores smooth; rhinophores and oral tentacles of similar size; 

 propodial tentacles present; dorsally with dense cerata, not arranged 

 in groups; colour transparent whitish with orange brown cerata. 



Habitat. On Macrocystis (as also noted by Schrodl, 1996) at 5-15 

 m depth, where the animals presumably graze on epiphytic hydroids. 



Records. Stations 1, 14. Elsewhere Seno Reloncavi to Magellan 

 Strait (Schrodl, 1996, 1997). Range: 42-54°S. 



Family SIPHONARIIDAE 



Siphonaria (Talisiphon) lessonii Blainville, 1827 



(Figure 4G, H) 



Siphonaria lessonii Blainville, 1827: 296, pi. 61, fig. 2, 2a. 

 Siphonaria (P achy siphonaria) lessoni - Hubendick, 1946: 21-22, 



fig. 4, pi. 1, figs 1-3 (anatomy). Olivier & Penchaszadeh, 1968: 



469^91, pi. 1, textfigs. 2, 3, 5 (radula, anatomy). Dell, 1971: 



214-215 (synonymy). 

 P achy siphonaria lessoni -Powell, 1951: 181. 

 Siphonaria (Talisiphon) lessoni - Morrison, 1963: 7 (synonymy). 



Marincovich, 1973: 42, fig. 95. 

 Siphonaria tristensis Leach, 1824 - Strebel, 1907: 170-172, pi. 3, 



figs 31-33. 



Description. Shell to 20 mm; high (rarely low) conical to cap- 

 shaped limpet, apex at about one third shell length from posterior 

 margin, posterior slope sometimes concave, basal outline asym- 

 metrically oval, with slight projection on right side (corresponding 

 to pneumostome opening of animal); sculpture smooth or with slight 

 radial ribs; colour pale with numerous fine dark brown to black 

 radial lines, interior dark brown with pale margin where exterior 

 dark rays show through. 



Habitat. Abundant on rocks on sheltered and exposed shores; in 

 upper eulittoral together with barnacles and Nodilittorina araucana, 

 extending into zones of Nacella and Mytilus, and often attached to 



Fig. 4 A. Xymenopsis muriciformis (20 mm). B. Xymenopsis subnodosus (23 mm). C. Pareuthria fuscata (30 mm). D. Pareuthria powelli (17 mm). E. 

 Nassarius gayii (12 mm). F. Adelomelon ancilla (juvenile; 18 mm). G, H. Siphonaria (Talisiphon) lessonii (15 mm). I. Chilina patagonica (15 mm). J, K. 

 Malletia magellanica ( 1 9 mm, 1 4 mm). L. Mulinia edulis (60 mm). M. Adelomelon ancilla (adult; 200 mm; Falkland Islands). N. Felaniella inconspicua 

 (18 mm). O. Zygochlamys patagonica (juvenile; 17 mm). (All specimens from study area except M; all NHM collection). 



