SYSTEMATIC 85 



Fissurella (Balboaina) picta (Gmelin) 

 Patella picta Gmelin, 1791, p. 3729. 

 Fissurella picta Hupe (Gay), 1854, p. 237. 

 Fissurella picta Rochebrune & Mabille, 1889, p. 70. 

 Fissurella picta Pilsbry, 1890, p. 144, pi. 45, figs. 9-1 1. 

 Fissurella picta Melvill & Standen, 1907, p. 98. 

 Fissurella picta Strebel, 1906, p. 83. 



Type locality. Strait of Magellan. 

 St. 51. Off Eddystone Rock, East Falkland Is., from 7 miles N 50 E to 7-6 miles N 63 E of Eddystone Rock, 



4 May 1926, 105-115 m. (small dead shells only). 

 Port Stanley, Falkland Is. (A. G. Bennett and J. R. le B. Tomlin). 



Range. Valparaiso, Chile (Pilsbry, Gay); Tierra del Fuego (Strebel); Santa Cruz, Punta Arenas 

 and Baie Orange (Rochebrune and Mabille); Port Stanley, Falkland Is. (Melvill & Standen and 

 Strebel). 



Length 17-5 mm.; breadth n-o mm.; height 4-0 mm. (St. 51). 



Length 6o-o mm.; breadth 39-0 mm.; height 16-0 mm. (Falkland Islands). 



Length 84-5 mm.; breadth 54-5 mm.; height 26-0 mm. (Falkland Islands). 



Length 86-o mm.; breadth 55-5 mm.; height 27-0 mm. (Falkland Islands). 



Fissurella (Balboaina) oriens Sowerby 

 Fissurella oriens Sowerby, 1834, p. 124. 



Fissurella oriens Pilsbry, 1890, p. 152, pi. 46, figs. 18, 19; pi. 34, fig. 58. 

 Fissurella oriens Strebel, 1906, p. 88, pi. 1, figs. 8-14; pi. 2, figs. 15-20. 

 Fissurella oriens Melvill & Standen, 1907, p. 97. 

 Fissurella oriens Strebel, 1908, p. 78, pi. 6, fig. 97a, b. 



Type locality. Valparaiso, Chile. 

 St. 51. Off Eddystone Rock, East Falkland Is., 4 May 1926, 105-115 m. (one small empty shell). 

 Port Stanley, Falkland Is. (ex Australian Museum). 

 Length 24-0 mm. ; breadth 12-0 mm. ; height 4-0 mm. (Falkland Islands). 

 Length 43-0 mm. ; breadth 23-0 mm. ; height 8-0 mm. (Falkland Islands). 

 Length 46-0 mm. ; breadth 27-0 mm. ; height 1 i-o mm. (Pilsbry). 



Range. Coast of Chile and Island of Chiloe (Pilsbry) ; various Magellan localities including Falkland 

 Is. (Strebel); Port William, Falkland Is. (Melvill & Standen, shore; Strebel, 12 m.). 



The two species occur together at the Falkland Islands, but do not seem to intergrade. The species 

 picta reaches a large size, has an ovate outline, and the length of the orifice is one-seventh to one- 

 eighth that of the shell; "oriens 1 is smaller, narrow, with parallel sides, and the length of the orifice is 

 one-sixth that of the shell. The former is white, conspicuously rayed with dark purplish brown and the 

 latter diffused greyish and reddish purple, in concentric zones and crossed by reddish radials. I have 

 no topotypic material of oriens, so cannot comment on the correctness or otherwise of applying the name 

 of a Chilean species to Falkland Islands material. 



Genus Megatebennus Pilsbry, 1890 

 Type (o.d.) : Fissurellidea bimaculata Dall, California 



Megatebennus patagonicus Strebel 



Megatebennus patagonicus Strebel, 1907, p. 98, pi. 2, fig. 23 a-/. 

 Megatebennus patagonicus Strebel, 1908, p. 79. 

 Type locality. Lennox I., Tierra del Fuego. 

 St. 57. Port William, East Falkland Is., 5! cables S 20 W of Sparrow Point, 16 Ma 1926, 15 m. (one example). 



