68 



Axis 9, diam. 14 lin. 



Hab. in Nov& HoUandia, 200 millia passuum ab Ostio Fluvii 

 Macquarrie. 



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

 imperforatd, pallide brunned, granis minutis albis aspersd ; spird 

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

 antice convejciusculo ; aper'urd ovato-ti-igond ; labiis incrassatis, 

 reflexis, albis, externa antice recto, in/Equaliter 3-dentato, dentibus 

 duobus intends obliquis approximatis, externo majore distante 

 compresso. 



Axis 7, diam. 11 lin. 



Hab. vulgaris in India Occidentali. 



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

 ratd, badid, Itevi, tenuiter striatd ; spird convexiusculd ; anfrac- 

 tibus planis, ultimo ventricoso, rotundato, obsoletissime in medio 

 carinato ; aperturd siibtrigond ; labiis incrassatis callosis, externo 

 antice inths dente parvo extus plied majore instructo. 

 Axis 4-4-, diam. 8 lin. 



Mr. Gray observed on this character that he calls that a tooth 

 which is solid, and that a plait which is marked externally by a 

 corresponding groove. Thus the Chondri of Cuvier have toothed 

 mouths, and the Pupce and Clausilia plaited. 



The exhibition was resumed of the new species of Shells contained 

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

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

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

 the Society were accompanied by observations and characters by Mr. 

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



Genus Pholas. 



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

 scription of the various sorts of Fholades, on account of the extraor- 

 dinary difference in the form of the same specits in different stages 

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

 in age, must be carefully 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 

 difi'erence in size of different individuals of the same species may 

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

 lest such difference should mislead" the adept also, let him too pro- 

 ceed cautiously, and when he finds a fully grown shell of half an inch 

 in length agreeing perfectly in proportions and characters with an- 

 other of two inches long, let him not conclude that it is a distii: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 dwarf. Let it be remembered that among the Cyprcea. it is not un- 



