154 ARCADE. 



Found in the stomachs of codfish in Casco Bay, in great numbers 

 (^Mig'hels) ; whole coast, laminarian region (^Stiuipson). Aljundant 

 on sandy and muddy bottoms. Cape Ann, tliirty fathoms ; Race 

 Point, twenty-two fathoms ; Broad Sound, six fathoms ; Grand 

 Manan {Stiinpsou) ; Greenland {3Idrch). 



The animal has the mantle freely open, forming no siphons ; the 

 foot large, hyaline, with a deep fissure and serrated edges, protruded 

 from the longer side. It is very active (^Stimpsori). 



Distinguishable from other species by its small size and tumid, 

 almost globose form, as well as by the number of teeth. 



Ociius YOL,DIA, MuLLER. 1832. 



Shell oblong-ovate, compressed, rostrate posteriorly ; with fine 

 concentric or oblique stria), covered with a, varnished epidermis ; 

 slightly pearly within. Pallial impression with a small sinus. An- 

 imal with a large foot, mantle open and ciliate, siphons adnate, long, 

 and very slender. 



Yoldia limatula. 



Tig. 62. 



Shell oblong-ovate, rostrated, veiy smooth and shining; beaks sub-central; 

 teeth twenty-two on the anterior, and eighteen on the rostrated side. 



Nucula limatula. Say, Amcr. Conch, pi. 12 (1831). — Gould, Iiiv. Mass. 1st ed. 98, fig. 



6-2. -De Kay, Nat. Hist. New York, 180, pi. 12, fig. 218. — Conrad, Amer. Mar. 



Conch. 30, ])1. G, fig. 1. — Hanley, Biv. 170, pi. 20, fig. 4. — Sowehby, Thesaiir. 



Conch. {Nucula), pi. 1, fig. 9. — Migiiels, Cat. Sliells of Maine, IG, and in Bost. 



Joiirn. Nat. Hist. iv. 322. 

 Yoldia limatula, Adams, Gen. ii. 548, pi. 12G, figs. 5, 5b. — Ciienc, Man. de Conch, ii. 



1 80, fig. 90.5. 

 Leda limatula, Stimpson, Shells of New England, 10 (1851 ). — S. S.mitii, Moll, of Long 



Island, 15, and in Ann. N. Y. Lye. vii. 



Shell transversely ovate, very much elongated, thin, lines of 

 growth very minute, otherwise smooth and covered with a beauti- 

 fully glazed, light green epidermis, with an occasional darker zone, 

 and two or three lighter radiations ; beaks nearly central, not promi- 

 nent, inclined backwards ; hinge-margin behind rectilinear nearly 

 to the tip, compressed, the compression not reaching the tip, which 

 is a little recurved, pointed, and not truncated ; anterior and basal 

 margin almost regularly rounded, entire ; interior bluish-white, 



