On Gadinia, a nexa Genus of Patdloid Shells. 

 Gadinia. 



Testa univalvis, non symmetrica, oblique conica ; vertice ob- 



tuso, subpostico. Apertura suborbiculata, irregularis ; cavi- 



tas simplex, sulco iu latere dextro prope limbum anticum, 



impressionis muscularis ; impressio muscularis elongata, ar- 



cuata, submarginalis. 

 Animal ignotum. 



This genus is instantly to be distinguished by the peculiar 

 groove, which is formed, there is little doubt, by the tube 

 that directs the air to the respiratory cavity of the animal, 

 with which unfortunately we are unacquainted. 



I have only observed one species, which, having been called 

 Le Gadin by Adanson, I have consequently named 

 I. Gadinia qfra. Testa oblique conica, alba, radiatim striato- 



costata subsquamosa ; vertice sublasvi ; marginibus crenu- 



latis. 



Patella afra. Gmelin 3715 ! Dillwyn. Rec. Shells, ii. 104-6 \ 



Patella n. 1. Schroeter. Einl. ii. 441. 



Le Gadin. Adanson Senegal. 33. t. 2.f. 4 ! 



Icon. Gaulter t. 9.f. 6. Martini i. 92 t. S.f. 34. 



Inhabits Coast of Africa. Coast of Cape Manuel and the 

 Island of Goree. Adanson. 



Shell white univalve not symmetrical, obliquely conical with 

 an obtuse vertex placed towards the hinder part, rayed with 

 many rather scaly rib-striae diverging from the apex ; the 

 aperture is nearly orbicular, crenulated, sometimes slightly 

 extended, on the right anterior lateral portion, just over the 

 groove; the cavity is simple, concave with a slight groove 

 near the front part of the right limb of the horse-shoe shaped, 

 sub-marginal muscular impression. 



Length and breadth about £ inch. 



This shell is not uncommon in collections, and maybe con- 

 founded with Siphonaria ; but in that genus the groove is 

 placed in the muscular impression, and divides it into two por- 

 tions. I had, in a paper which it was my intention to have 

 published the beginning of last year, called the latter genus 

 Liria, believing the Patella tristensis of Dr. Leach to be Le 

 Liri of Adanson and consequently the Patella perversa of 

 Gmelin; but as Mr. G. Sowerby has lately published this shell 

 with two or three others under the generic name of Siphonaria, 

 it should be adopted. 



He has however in my opinion fallen into the common error 

 M m 2 of 



