217 



LuTRARiA CAPAX. Testa magnifica, ventricosa, ovato-rotun- 

 data, antice rotundata, postice sub-triangularis, truncata, valde 

 hians, concentrice undulato-striata, epidermide luteo-viridi (post 

 costam medianum radiatim corrugate) induta ; umbonibus tumi- 

 dis, incumbentibus, attigentibus : cardo validus ; fovea lata, ob- 

 lique triangular!; dente cardinal! crasso, erecto, plicate, basi 

 appendiculato ; dentibus lateralibus compressis, conspicuis. In- 

 terior calcarea ; sinu siphonali linguiformi, dimidiam longitudinis 

 testae attigente. Long. 5J ; alt. 4 ; lat. 3 poll. Hah. Puget 

 Sound. 



No other species approaches this in size and capacity. 



Mesodesma munda. T. parva, solidula, convexiuscula, 

 ovato-triangularis, Isevis, epidermide stramineo induta ; natibus 

 post-medianis, acutis ; margine dorsali vix arcuato, postice subito 

 declivi ; latere antico angustato, acuto ; latere postico rotundato ; 

 margine ventrali valde arcuato. Interior flavescens, cicatricibus 

 impressis: cardo dentibus validis instructus. Long. | ; alt. f ; 

 lat. Y^o poll. Hah. Mangsi. 



Distinguished from M. striata by its more compressed, less 

 angular form, its short, broad, rounded anterior end, there being 

 no angle except at the beaks, and by its smooth surface. 



Pandora cistula. Testa solida, alba, valde inequilateralis, 

 falciformis, antice rotundata, postice anguslata, truncata : valva 

 plana tenuis, submargaritacea, concentrice undulata; margine dor- 

 sali subrecto, late inflecto, unidentato, dente brevi, elevato, trian- 

 gular! munito : valva concava solidior, ossea, tumida, postice 

 costato-angulata, edentula, fossa ligamentali et costa anticali 

 instructa ; margine dorsali concavo ; margine ventrali valde 

 arcuato. Long, l^ ; lat. ^ ; alt. lj\ poll. Hah. East Pata- 

 gonia. 



More solid, more concave, and more elongated than any 

 species I am acquainted with. The upper valve of a small speci- 

 men from the same locality is semicircular, but more acute 

 anteriorly than posteriorly. 



OsTEODESMA BRACTEATA. Tcsta parva, tenuis, transversa, 

 inequilateralis, ovato-falcata, ventricosa, margaritacea, epider- 

 mide fusco radiatim creberrime rugoso induta; latere antico 



