ANODONTA. 537 
Mazatlan Shells, p. 117°; Fisch. & Crosse, Miss. Scient. Mex., Moll. ii. p. 534, t. 68. 
figg. 2, 2a'. | 
Anodon ciconia, Sowerby, in Reeve’s Conch. Icon. xvil., Anodon, t. 29. fig. 115 a’. 
Anodon ylaucus (Lam.), Sowerby, in Reeve’s Conch. Icon. xvil., Anodon, t. 27. fig. 105 a°. 
Anodonta glauca (Val.), Clessin, in Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, Anodonta, p. 222, 
t. 73. fig. 4 (copied from Sowerby) *. 
Anodonta glauca, Lam., var. sinaloensis, Crosse & Fisch. Journ. de Conch. xxxi. p. 219 (1883) °. 
Remarkable for its large size, conspicuously low form, and the upwardly bent and gaping fore part, which 
give it the appearance of a species of the South-American genus Leila; but differing from them in having 
the pallial line running direct to the impression of the posterior adductor, without an acutangular 
sinus. 
a. Long. 126; alt. vert. 61, ale 67, diam. 43 millim. Vertices in 3 long. 
B. ng LOB; 9 56, ,, 56, ,, 354 ,, » Bon 
C. ” 102 5 ” 57%, » 574, 9 35 ” ” 3 ) 
a. 95 ; 3 503, ,, 53, ,, 343, 9 3 
é. i 93 ; 3 49, , 53, , 34 ,, - x 
f. ” 87 3 ” 45, 2” 50, 9 28 ” ” 3 ” 
g 2 ive ” 37, 4, 43, » 26 ” ” 4 ” 
Hab. N.W. Mexico: Mazatlan, not uncommon (MMelchers, in coll. Dunker ; Reigen,? ; 
forrer ; Richardson). | 
The measurements given above, all from Mazatlan shells obtained by various 
collectors, indicate a moderate variability in the relation of the height to the length. 
The outside is constantly of a yellowish-olivaceous colour. ‘The inside is, according to 
Carpenter °, salmon-colour, in the young shell silvery, light, or flesh-colour; in adult 
shells (a-/ ) it is also silvery, with a faint reddish or orange hue, in the evidently young 
specimen (y) pale bluish. In one example before me (Tab. XLI. fig. 4) there are curious 
oblique scratches inside, looking like casts of the swollen gills, and others, narrower 
and less oblique in the fore part, like casts of the mantle; these latter are also more 
or less distinctly visible in some other specimens. The sinulus of the ligament is 
deeply triangular, bent forwards. 
The figure given by Sowerby 5, as an old example of A. ciconéa, fig. 115 6, differs so 
much in general outlines that I doubt if it belongs to the same species. 
The specific name refers to a fancied resemblance of the shell to the bill of a 
stork. Fischer and Crosse* give, besides Mazatlan, as another locality, ‘ Rio del 
Presidio,” quoting Forrer as authority. The specimens acquired from this collector 
bv the Berlin Museum bear the label ‘ Presidio” simply, Presidio de Mazatlan being 
the name of the inland town, to distinguish it from the port, Puerto de Mazatlan. 
Pacuyanopon, v. Mart. 
19. Anodonta luteola. 
Anodonta luteola, Lea, Proc. Acad. Phil. 1858, p. 118°; Journ. Acad. Phil. (2) iv. p. 267, t. 43. 
fig. 147°, = Obs. Gen. Unio, vii. p. 85, t. 43. fig. 147°; Clessin, in Martini & Chemnitz, 
Syst. Conch.-Cab. ed. 2, Anodonta, p. 122, t. 37. figg. 1, 2 (copied from Lea)*; Tate, Am. 
Journ, of Conch. y. p. 160 (1870) ’. 
BIOL. CENTR.-AMER., Terr. and Fluviat. Mollusca, Octoler 1900. 68 
