128 AUCIiiJE. 



Biillii, Limiieus, etc. 

 Pkuwrbis, Miiller. 

 Turho, Costa. 



Bulimus, Briitruiere, Poiret. 

 Limnea, Sowerby. 



Type, PJu/sa fontinalis, Liun. ; Europe. 



liange. Europe ; Asia ; Africa ; America. 



Shell fluviatile, horny, thin, spiral, sinistral, generally ovate 

 acuminated ; outer lip sharp, simple ; inner lip expanded, con- 

 tinuous with the columella ; columella tortuous, single-plaited. 



260. Physa coromandelica, Dunlcer. 



I'/ii/sa coromandelica, Dunker, Malak. Bliitt. 1862, p. 150. 



Orir/inal description : — Testa subovata tenuis, fusco-cornea, sub- 

 diapliana, anfractibus quinis carinatis, per longitudinam striatis, 

 sutura distincta divisis instructa ; spira parum exserta, ob carinam 

 prominentem scalata ; anfractus embryonalis vel apex obtusius- 

 cuhis; apertura ovato-oblonga obhqua ; spira duplo major; labrum 

 acutum in margine superiore angulatura. 



Alt. 11, diam. 5-5 mm. 



Hah. Coromandel. 



Class PELECYPODA. 



Order TETR A Bll A X C H 1 A. 

 Suborder MYTH ACE A. 



Family ARCID.^. 



Siibfaniily ARCIN.E. 



Shell eitlier equivalve or inequivalve, oval, rounded or trape- 

 zoidal, covered with a periostracum ; ligament spreading over a 

 considerable external area, or confined to a small depression ; 

 hinge multi-dentate, the teeth short or lamelliform ; adductor 

 scars extended, subequal; pallial line simple; interior of shell 

 not nacreous. 



Animal, with the exception of Scaplnda, marine; foot large, 

 broad, bearing a byssiferous groove and frequently a byssus ; tlie 

 adductor muscles in both valves of about equal size ; siphons 

 absent; gills oblique, either equal or unequal; palpes simple 

 without posterior appendages. 



Distrilmtion. Tropical and subtropical seas, and rivers of 

 Eastern India and Burma far bevond the limits of tide. 



