57 



July 8, 1834. 



William Yarrell, Esą., in tlie Chair. 



A Letter was read addressed to the Secretary by M. Julien 

 Desjardins, Corr. Memb. Z, S., dated Mauritius, January 10, 1S34. 

 Itaccompanied a coUection of objects of Zoology, consisting chiefly 

 of Mammalia and Birds, which were exhibited to the Meeting. 



Mr. Gray exhibited various undescribed Shells, chiefly contained 

 in his own collection. He characterized them as follovvs : 



Unio Nov^ Hollandi^. Un.testd oblongo-elongatd, gracili, 

 solidu ; antice subcompressd, Icevi, rotundatd, postice subventri' 

 cosd, productd, tuberculis magnis incecualibus in seriebus curvatis 

 radiantibus dispositis ; disco argenteo purpureo maculato, margine 

 iiiferiore antice crassissima ; dente cardinali anteriore parvo, 

 pariim elevato, bituberculato ; dentibus posterioribus parvis, sub 

 cartilaginis margine posteriore positis ; periostracd crassii, nigra. 

 Hab. in Novae Hollandiae flumine Macąuarrie, 70 circiter mill. 

 ab ėjus ošti o. 



Anodon Parishii. An. testą ovatd, ventricosd, solidd ; antice 

 compressd, subproducta, subgracili, postice expansd, dilatatd, 

 rotundatd; margine cardinali rectd, marginis injerioris dimi- 

 dium longitudine cequante ; disco margaritaceo-albo ; periostracd 

 brunneo-nigrescente. 

 Long. 74-, alt. 3-| poli. 

 Hab. in fluviis Paraguayae. 



The submarginal scar has an acute inflection under the hinder 

 muscular one ; and there are several small unequal scars behind 

 that of the acterior adductor, as well as others, also unequal, under 

 the umbones. 



Anodon penicillatus. An. testd ovata, ventricosa, crassd, 

 solidiusculd, Icevi; antice subcompressd, rotundatd, subgracili, 

 postice oblique truncatd ; ad marginėm inferiorem postice di- 

 latato-rotundatd; disco albo, lineis angularibus brunneo-ni- 

 grescentibus prope cicatricem muscularem submarginalem notato; 

 periostraca olivacea, Icevi. 

 Hab. in fluviis Paraguayae. 



The black lines of the inside of the shell are deposited along the 

 upper edge of the submarginal muscular scar, and are gradually co- 

 vered by the pearly layer deposited by the surface of the mantle 

 over the scar ; the interior ones, being the most thickly covered, 

 are the lightest in colour. 



No. XIX. — Proceedings of the Zoological Societv, 



