210 TKOCEEDINGS OF THE MALACOLOGICAL SOCIETr. 



DESCEIPTION" OF TRIBAGNA OBESA, n.sp., FROM THE 

 PHILIPPINES. 



By G. B. SoAVEEBY, r.L.S., etc. 



Read Wth November, 1S98. 



Amongst a large quantity of marine shells collected many years ago 

 in the Philippine Islands, that has recently come to light, are several 

 species of Tridacna, including one Avhich appears to be new to science. 

 The collection contains many T. squamosa (Lamk.), of various sizes, one 

 specimen of which, exceeding a foot in length, has the large vaulted 

 scales, well preserved throughout, thus clearly distinguishing the 

 species from T. gigas (Linn.). There are also specimens, in various 

 stages of growth and development, of T. elongata (Lamk.), and 2\ crocea 

 (Lamk.), as Avell as two shells of T. serrifera (Lamk.) and three of 

 a very distinct form, which I propose to call — 



Teidacna OBESA, n.sp. 



/ 



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Testa ovata, gibhosa, ponderosa, sordide luteo-albida, antice 

 truncata, postice acuminata, undique confertim concentrice striata, 

 costis 4-5 latis, paulo elatis, levissime rotunde convexis, hand 

 squamosis instructa, interstitiis amplis, radiatim striatis ; margo 

 dorsalis posticus elongatus, rectiusculus, anticus brevior, recte declivis ; 



