CYPRINIDjE. 443 



composed of three teeth in each valve, the middle tooth in 

 the left, and the hinder one in the right valve bifid ; lateral 

 teeth none; ligament external, marginal. Pallial sinus very 

 deep and narrow, ascending obliquely towards the hack of 

 the shell. 



Syn. Glauconome, Gray, not Goldfuss. 



Ex. G. rugosa, Reeve, pi. 110, fig. 3. Shell, G. rugosa, 

 fig. 3, a, 3, b. 



The species of the genus Glauconomya are almost exclu- 

 sively confined to the Philippine Archipelago, where they 

 live in the sandy mud at the mouths of rivers, and even in 

 the estuaries where the water is partially fresh. They bury 

 themselves in the soil, and appear to be very similar in their 

 habits to some of the Solens. One species inhabits the 

 river Ganges, and another the rivers of China. The family 

 differs from that of Solenitke in the number and disposition 

 of the hinge-teeth ; and from Venerida in the form of the 

 teeth, the union of the mantle-lobes, in their fresh-water 

 habitation, and in the shells being covered with a hard, 

 green epidermis. 



Species of Glauconomya. 



angulata, Reeve. radiata, Reeve. 



cerea, Reeve. rostralis, Desk . 



Chiuensis, Gray. rugosa, Reeve. 



corrugata, Reeve. straminea, Reeve. 



curta, Hanlcy. virens, Linn. 

 psamrnotella, Desk. 



Fam. CYPRlNIDiE. 



Palpi narrow, elongate. Mantle open in front and be- 

 neath, simple, united behind by a curtain ; siphons very 



