142 AXEL A. OLSSON 



scars in adjacent position. The valves were probably united by a ligament 

 attached to a linear scar along the dorsal margin just in front of the beaks. 

 Although Julia is now known to belong to the sacoglossate O'pisto- 

 branchs, it is mentioned here because of its long association with the 

 Pelecypoda. Single valves of Julia have a decidely Tectibranch-like aspect 

 as some authors have previously noted. For a discussion of these curious, 

 bivalved snails, the reader should consult the following: 



S. Kawaguti and K. Baba, 1959, A preliminary note on a tivo-'val'ved sacoglossan 

 gasteropod, Tamanovalva Umax. Japan. Biological Journal, Okayama University, 

 vol. S, Nos. 3-4, pp. 177-184; Kawaguti, S., Formation of the bivalve shell is a 

 gastropod, Tamanovala Umax. Proc. Japan Academy, vol. 35, No. 10, pp. 607-611, 

 5 figs.; A. Myra Keen, 1960, The riddle of the bivalved gastropods, The Veliger, 

 vol. 3, No. 1, pp. 28-30; J. P. E. Morrison, 1960, Notes on the bivalved univalves; 

 W. J. Clench, The bivalve gastropod and the Opisthobranchs. (Last two read before 

 American Malocological Union, 1960.) 



Genus JULIA Gould, 1862 



Type species by monotypy, Julia exquisita Gould. Recent, Hawaiian 

 Islands. 



With characters of the family. 



Julia theeaphora (Carpenter) Plate 17, figure 5 



Smaragdinella theeaphora (Nutt.), Carpenter, 1875, Cat. Mazatlan Shells, Brit. Mus., 



p. 533, No. 692. 

 Julia equatorialis Pilsbry and Olsson, 1944, Nautilus, vol. 57, No. 3, pp. 86, 87, pi. 9, 



figs. 10, 11. — Arthur Day Howard, 1951, Nautilus, vol. 64, No. 3, pp. 84-86. 



The shell is small or minute, usually between 2 and 3.8 mm. in length. 

 When fresh, the color of the shell is green or greenish yellow, often with 

 brown stripes, but on weathering it soon becomes white. The valves are 

 moderately convex, subquadrate, the short, posterior side pointed at the 

 end. The texture of the valves is heavy, subtranslucent so that the markings 

 of the exterior often show plainly in the interior. The greatest inflation of 

 the valves is placed in front and below the beaks. 



Although rare in collections, this species is now known to have a 

 general distribution throughout the Panamic-Pacific faunal province. Be- 

 cause of its small size and often worn appearance it is generally overlooked 

 in picking of shell drift. 



A manuscript drawing of Snuiragdinella theeaphora, after the type 

 specimen by Carpenter in the library of the Department of Mollusks, U. S. 

 National Museum, shows that species to belong to the genus Julia. It seems 

 likely, therefore, that J. equatorialis represents the same form. 



Range — Lower California to northern Peru. Mexico: Mazatlan (Car- 

 penter); Socorro Island and Cape San Lucas (Howard). Panama: Bucaro. 

 Colombia: Isla del Gallo. Ecuador: Puerto Callo; Punta Centinella on 

 Santa Elena Peninsula. Peru: Caleto Sal (types of 7. equatorialis). 



