128 



Bulla, Linnaeus, etc. 

 Planorbis, Miiller. 

 Turbo, Costa. 



Bulimus, Bruguiere, Poiret. 

 Limnea, Sowerby. 



TYPE, Physa fontinalis, Linn. ; Europe. 



Range. Europe ; Asia ; Africa ; America. 



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

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

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



260. Physa coromandelica, Dunker. 



Physa coromandelica, Dunker, Malak. Blatt. 1862, p. 150. 



Original description : Testa subovata tennis, fusco-cornea, sub- 

 diaphana, anfractibus quinis carinatis, per longitudinam striatis, 

 sutura distincta divisis instructs ; spira parum exserta, ob carinam 

 prominentern scalata ; anfractus embryonalis vel apex obtusius- 

 culus; apertura ovato-oblonga obliqua ; spira duplo major; labrum 

 acutum in margine superiore angulatum. 



Alt. 11, diam. 5*5 mm. 



ffab. Coromandel. 



Class PELECYPODA. 



Order TETR A BRANCHI A. 

 Suborder MYTILACEA. 



Family ARCID^E. 



Subfamily ARCING. 



Shell either 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 5 

 hinge multi-dentate, 'the teeth short or lamellif'orm ; adductor 

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

 not nacreous. 



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

 broad, bearing a byssiferous groove and frequently a. byssus ; the 

 adductor muscles in both valves of about equal size ; siphons 

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

 without posterior appendages. 



Distribution. Tropical and subtropical seas, and rivers of 

 Eastern India and Burma far bevoml the limits of tide. 



