68 



Axis 9, diam. 14 lin. 



Hab. in Nova Hollandia, 200 millia passuum ab Ostio Fluvii 

 Macąuarrie. 



Helix granifera. Hel. testd conicd, orbiculari, depressiuseuld, 

 imperforatd, pallide brunned, granis minutis albis aspersd ; spird 

 convexu, obtusd ; anfractibus vix elevatis, ultimo acute carinato, 

 antice convesiusculo ; aperturd ovato-trigond ; labiis incrassatis, 

 reflexis, albis, externo antice recto, incegtialiter '3-dentato, dentibus 

 duobus internis obliąuis approximatis, externo majore distante 

 compresso . 



Axis 7, diam. 11 lin. 



Hab. vulgaris in ludia Occidentali. 



Helix pachygastra. Hel. testd orbiculari, depressd, imperfo- 

 ratd, badiu, Icevi, tenuiter striatd ; spird convexiusculd ; anfrac- 

 tibus planis, ultimo ventricoso, rotundato, obsoletissime in medio 

 carinato ; aperturd subtrigond ; labiis incrassatis callosis, externo 

 antice inliis dente parvo extus plicd majore instructo. 

 Axis A\, diam. 8 lin. 



Mr. Gray ob.«ened on this character that he calls that a tooth 

 Avhich is solid, and that a plait which is marked extemally by a 

 corresponding gi'oove. Thus the Chondri of Cuvier have toothed 

 mouths, and the Pupce and Clausilice plaited. 



The exhibition was resumed of the nevv species of Shells contained 

 in the coUection formed by Mr. Cuming, chiefly on the Western 

 Coast of South America and among the islands of the South Pacific 

 Ocean. Those brought on tlie present occasion under the notice of 

 the Society \vere accompanied by observation.s and characters by Mr. 

 G. B. Sovverby, and comprised the following species of the 



Genus Poolas. 



" The utmost caution is necessary in the examination and de- 

 scription of the various sorts of Pholades, on account of the e.\traor- 

 dinary difference in the form of the šame species in different stages 

 of grovvth. The addition of accessory valves also, as they increase 

 in age, niust be carefuliy observed, in order to guard against too 

 implicit a confidence in their number and form. And though I 

 might be considered guilty of asserting a truism by stating that the 

 difierence in size of aifferent individuals of tlie sanie species may 

 and sometimes does mislead the tyro in the science of Malacology ; 

 lest such difference should mislead' the adejjt also, let him too pro- 

 ceed cautioiisly, and when he finds a fully grown shell of halfan inch 

 in length agreeing perfectly in proportions and characters with an- 

 other of t\vo inches long, let him not concUide that it is a distir.ct 

 species, but if he can find no other difference except that which 

 exists in their dimensions, let him consider the one a giant, the other 

 a dvvarf. Let it be remcmbered tliat among the Cyprcea it is not un- 



I 



