952 PELECYPODA [Eulamellibratichia. 



Subgen. 3. ANGULUS, Megerle (em.), 1811. 



Anyulus, Megerle von Miihlfeldt, Mag. Gesellsch. Naturforseh. Freunde, 

 Berlin, 1811, 47. Type: Tell inn lanrmlata. L. Fuberlina, Gray, 1851. 

 Tellinula, Auct. 



Shell elongated, mostly small, compressed, with the posterior 

 end angularly pointed and not twisted, the surface smooth or with 

 fine concentric sculpture ; nymphs short and prominent, the liga- 

 ment short ; hinge with a single adjacent lateral well developed in 

 the right valve anteriorly ; internally a thickened ray passes from 

 the uinbo just behind the anterior adductor-scar and 1 or 2 narrower 

 similar rays in Jiront of the posterior adductor, often stronger in the 

 left valve, the posterior rays sometimes obsolete ; sinus largely or 

 wholly coalescent with the pallia! line below. (Dall.) 



Eocene to Recent. 



KEY TO SPECIES. 



A. Anterior end shorter, posterior end produced, subangular . . nlhn. 



B. Beaks at or very near the middle. 



. Posterior end angled, trigonal ; ratio of height to length, 1:1-6 glabreUn. 

 mi. Posterior end distinctly rostrate ; ratio of height to length, 



1:1-8 . . . . Spencer i. 



1. Tellina alba, Quoy and Gaimard, 1835. Plate 59, fig. 14. 



Tellina alba, (}. & G., Voy. Astrol., iii, 1835, 500, pi. 80, f. 1-3 ; Dieff. N.Z., 

 254 ; Hanley, in Thes. Conch., i, 1846, 311, pi. 62, f. 193 ; Conch. Icon., 

 xii, 1866, f. 180 ; R timer, Conch. Cab., x, 1871, 255, pi. 48, f. 10-12 ; 

 (lit. Lif-t, 42 ; M.N.Z.M.. 143. T. albuu-Un, Lamarck : Button, C.M.M.. 

 66 ; not of Lamarck. 



Shell ovato-subtrigonal, rather thin, subpellucid, inequilateral, 

 anterior end shorter, compressed, white, concentrically striated, 

 slightly gaping behind. Beaks contiguous, somewhat raised, acute, 

 directed slightly backwards. Anterior end rounded and obsoletely 

 plicated above, the dorsal margin lightly convex and slowly descend- 

 ing ; posterior end produced, subangular, distinctly folded, the dorsal 

 margin convex, more rapidly descending than the anterior slope : 

 basal margin broadly and regularly rounded. Sculpture consisting 

 of very fine and dense concentric lines, which are getting much stronger 

 on the posterior dorsal slope ; there are 3 to 4 obsolete radial anterior 

 ridges and 2 folds near the posterior dorsal margin. Epidermis very 

 thin, somewhat iridescent. Colour pure-white. Interior bluish-white, 

 shining, with distinct anterior and posterior rays. Hinge : Right 

 valve with 2 oblique cardinals, the posterior bifid, 1 slightly raised 

 anterior lateral close to the cardinal ; left valve with 2 cardinals, the 

 anterior bifid. Ligament short, deep - set, the nymphs well deve- 

 loped. Adductor - scars unequal, the anterior high and narrow, the 

 posterior smaller, subquadrangular. Pallial sinus deep, triangular, 

 broadly rounded in front, where it nearly reaches the muscle-scar. 



Length, 58 mm. ; height, 38 mm. ; diameter, 9 mm. 



Type in the Mus. Hist. Nat., Paris. 



