30 



Saxidomus aratus. T. crassa, exalbida, OTatoquadrata, epider- 

 mide tenui rufa indiita, liris profundis recliventibus concentricis arata ; 

 umbonibus ad trientem anteriorem positis ; extremitate postica sub- 

 quadrata, oblique truncata, angulis rotundatis, modice lilante ; delivi- 

 tate umbonali obtuso ; extrem. antica minus elevata, rotundata, absque 

 lunula : cavositas alba, margine simplici : cardo validus, dentibus in 

 utraque valva 4, in v. dextra posteriori, in v. sinistra anteriori multo 

 majori. Long. 4.5 : alt. 3 ; lat. 2 inches. Inhabits San Francisco. 



Smaller than S. XuttaUi, the posterior dorsal portion more elevated, 

 the valve more regularly convex, the beaks less prominent, which 

 with the furrows and epidermis give it very distinct characters. 

 Venus maxima Phil, cannot be very different from it. 



Tapes verxicosa. T. solida, oblongo-ovata, yentricosa, nitida, 

 superne levis alibi concentrice sulcato-plicata, fulva flavido maculata 

 et radiis hepaticis interruptis 4 ornata ; umbonibus vix antemedianis ; 

 lunula lanceolata ; facie dorsali antica excavata ; extremitate antica 

 acute rotundata ; margine dorsali postica subrecta, extremitate late 

 rotundata, subtruncata ; marg. ventrali lente arcuata ; margine 

 interna simplici. Long. 3 ; alt. 2 ; lat. 1.5 poll. Lihabits Kagosima 

 Bay and off Hakodadi Cape, in coarse sand, 20 fathoms. W. S. 



One of the most beautiful of the group, allied to T. sulcata, with 

 which it agrees in form and size ; it is more brilliantly colored, and 

 the sulci are less general. T. laterisulca is differently colored, and the 

 sulci end more abruptly. It is more brilliantly varnished than any 

 other species. The young are nearly destitute of sulci. 



Venus (Mercenaria) Stimpsoxi. T. solida, einerea, ovato-cordata, 

 satis convexa, laminis erectis concentricis confertis disposite ornata ; 

 umbonibus antemedianis eminentibus, acutis, approximatis ; facie 

 dorsali antico concavo ; lunula profunda ; extremitate antica com- 

 pressa, rotundata ; facie dorsali postica arcuata, declivi, impressa, 

 nihil nisi striata ; extremitate postica satis acuta : cardo validus ; 

 cavositas et apophysis ligamentalis aurantiaci ; sinu siphonali minime 

 profundo ; margine interna simplici. Long. 3.7; alt. 3.3; lat. 1.7 

 poll. Inhabits Hakodadi, 6 fathoms. AY. S. 



A fine species analogous to American Atlantic forms. Resembles 

 F. mercenaria and V. Mortoni, but is less soHd and less ventricose 

 than either, having the white interior and closely laminated exterior 

 of the latter. 



Vexus puellula. T. parvula, subcircularis, ovato-triangularis, 

 solida, straminea rufo bi-vel tri-radiata ; umbonibus medianis, emi- 

 nentibus, purpurcis ; extremitate antica rotundata ; margine dorsali 

 postica angulata, rapide declivi, apice truncato ; margine ventrali 

 semicirculari ; disco radiis numerosis elevatis et costis compressis- 

 alveolate, costis marginem posticam baud attigentibus. Cavositas 



