t^^l

132 uNioNiniE.
Suborder SUBMYTILACEA.
Family UNIONID^.
Subfamily UNIONIN.^.
Shell nacreous, covered with a more or less thickened periostracum;
umbones generally corrugatedly sculptured; ligament
somewhat elongated, projecting; hinge teeth bearing, the teeth
usually strong, arranged as cardinals and laterals ; pallial line
generally simple. Animal with labial palpes somewhat drawn out,
projecting posteriorly; embryos borne in the outer or in all four
gills.
Distribution. Temperate and tropical regions of the world. A
single genus occurring in the Indian Eegion.
Genus SOLENAIA.
Solenaia, Conrad, Am. Journ. Conch, iv, 1869, p. 249.
TYPE, Mycetojnis emarginatiis, Lea, from Siam.
Mange. South-Eastern Asia and China, one species only from
India.
Shell elongated, thin; gaping anteriorly ; hinge with a long,
acicular, lateral tooth in each valve, slightly developed.
The soft parts appear to be unknown, though Ifischer notes in
his paper 'Observations sur les genres JfycetojjMS et Solenaia''*
that the animal retains an upright position in a hole which it
bores in the earth, which is often very hard, the manner of boring
being unknown. The siphons are placed above, the valves gaping
apart, the foot is turgescent having the anterior extremity much
swollen in the form of a bowl.
264. Solenaia soleniformis {Benson).
Solenaia soleniformis (Benson), Simpson, Syn.Naiades, Washington,
D.C., Smiths. Inst., Nat. Mus. Proc. xxii, 1900, p. 656.
Anodonta soleniformis, Benson, J. A. S. B. v, 1836, p. 750.
Margaron (Unio) henaoni, Lea, Syn. 1870, p. 57.
Mycetoptts bensonianus, Lea, H. & T., C. I. 1876, pi. 9, fig. 1 ;
Pffltel, Conch. Sam. iii, 1890, p. 186.
Spatha soleniformis, Fischer, J.Conchyliol., Paris, xxxviii, 1890,
p. 94.
Original description :—Testa elongatissima, postice angustata,
extremitate rotundata; antice latiore, sub-alata, extremitate
* J. ConchylioL, Paris, xxxviii, 1890, p. 11.