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NODULAEIA. 147
Unio crispisulcaius, Lea, A. M. N. H. x, 1862, p. 193; Sowerby,
Coneh. Icon, xvi, 1866, pi. 49, fig. 262.
MargaroH ( Unio) crispisulcaius, Lea, Syn. 1870, p. 149.
Original description :—Testa transverse subovata, subinaBquilaterali;
antice rotundata, postice superne descendente, leviter
angulata, demum obtuse angulata, crassiuscula, compressiuscula;
disco convexiusculo minutissime radiatim rugoso-costulato. costulis
nonnuUis acute divaricatis, posterioribus latioribus; umbonibus
prominentibus, coiitiguis, apicibus acutiusoulis ; epidermide luteoolivaeea,
postice fuscata, hie illic nonnunquam viridiscente;
dentibus cardinalibus utriusque valvsB duplicibus, lamellatis, lateralibus
obliquis, modice elongatis, valvse sinistras duplicibus:
niargarita caeruleo-albida iridescente.
Long. 28, lat. 45, diam. 16 miu.
Hab. Bangong Eiver near Thyet-Myo, Burma (W. Theobald);
Pegu (Indian Mus. Coll.).
To the above description is appended the following note :—
" The anterior cicatrices are distinct, the posterior coniluent,
the apical ones above the moderate angular cavity, and running
under the cardinal tooth.
" The delicate sculpture over the whole disk of this shell is
peculiar. In form it does not approach any Gangetic type."
A well-marked and apparently very constant form, the large
series of about twenty-three specimens in the Indian Museum
Collection, from the Irrawaddy near Thyetmio and Pegu, practically
showing no variation whatever.
283. Nodularia (Eadiatula) lima, Simpson.
Nodularia {Radiatida) lima, Simpson, Washington, D.C., Smiths.
Inst., Nat. Mus. Proc. xxii, 1900, p. 820.
Unio radula (Benson), Hanley, Rec. Biv. Shells, Supp. 1856, p. 382,
pi. 23, fig. 41; H. & T., C. I. p. 5, pi. 10, fig. 3.
Dysonomia radida, Rochebrune, Bull. Sac. Philom. Paris vi, 1882,
p. 42.
Original description :—Transversely oboval, inequilateral, not
very thick, rather compressed, olivaceous, scul'-' ired as in U. scobina,
but rather more linearly and transver^ ,y ; ventral and front
dorsal edges convex and subparallel; hinder extremity rounded,
narrower: umbonal ridge inconspicuous, umbonal slope simple ;
neither the eroded umbones nor the ligament prominent; nacre
bluish ; umbonal cavity shallow; hinder tooth strong, complicated ;
front lateral tooth elongated, a little curved.
Long. 19, lat. 32 mm.
Idab. Assam ; Siliguri and Sikkim (Indian Mus. Coll.).
Extremely variable in sculpture and form; in some specimens
the corrugations extend over the whole surface of the shell,
while in others they are confined merely to the umbonal region;
in general outline it varies from ovate to trapezoidal as the
L2