132 ITMONIDjE. 



Suborder SUBMYTILACEA. 

 Family UNION TD^E. 



Subfamily UNIONIN^E. 



Shell nacreous, covered with a more or less thickened perio- 

 stracum; 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. Jouru. Conch, iv, 1869, p. 249. 

 TYPE, Mycetopus emarginatus, Lea, from Siarn. 



Range. 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 Fischer notes in 

 his paper * Observations sur les genres Mycetopus 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. 



Maryaron ( Unio) bensoni, Lea, Syn. 1870, p. 57. 



Mycetopus bemonianus, Lea, H. & T., C. I. 1876, pi. 9, fig. 1 ; 

 Peetel, 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. Oonchyliol., Paris, xxxviii, 1890, p. 11. 



