85 



natibus sub-medianis, tumidis, obliquis ; lunula profunda, late 

 cordata : intus pallida ; margine crenulato : cardo validus; dente 

 postico valvar sinistra? longitudinali ; dente antico biramoso. 

 Long. If; alt. 1| ; lat. T % poll. Hab. Mangsi Island. 



In general characters it is allied to V. verrucosa, but is more 

 orbicular, more tumid, and its sculpture far more delicate and 

 elaborate, besides being beautifully ornamented with tent-like 

 markings in the intercostal spaces. 



Venus calcarea. Testa ovato-rotundata, alba, crassa, inequi- 

 lateralis, postice subtruncata, striis concentricis, irregularibus, 

 remotis, lamellosis signata ; natibus acutis, attigentibus ; lunula 

 duplici, ovato-lanceolata ; intus candidissima ; margine crenu- 

 lato. Long. 2J-; alt. 2; lat. If poll. Hab. New Zealand. 



Venus rigida. Testa solida, transversa, ovato-ventricosa, 

 inequilateralis, desuper visa acute ovalis, sordide alba, striis con- 

 centricis reflexis, utroque laminosis, et striis crassis radiantibus 

 decussata; decussationibus anterioribus punctatis ; umbonibus 

 elevatis, anteversis, contiguis : lunula lata, vix circumscripta : 

 latere antico angustato, rotundato ; latere postico late et oblique 

 truncato ; margine dorsali rectiusculo; cardine in dextra valva 

 dentibus duobus fissis, in valva sinistra dente unico fisso : intus 

 porcellana ; margine crenulato. Long. 2 ; alt. If; lat. l-£. poll. 

 Hab. Puget Sound ; Straits of De Fuca. 



Has the form and general aspect of Saxidomus Nuttalli, Con- 

 rad, in which the hinge teeth are quite different, and there are 

 no traces of diverging lines. The sculpture is much finer than 

 in V. Do?nbeyana, and more like that of V. decussata. It varies 

 considerably in its size and proportions, being often much more 

 expanded. One specimen measured in length 3£ ; height 2J- ; 

 breadth 1^ inches. 



Arca sobria. Testa transversa, inequilateralis, rhomboidea, 

 alba, costulis numerosis radiantibus, posticis majoribus, rugosis, 

 instructa, et undulis remotis concentricis subreticulata ; latere 

 antico angusto, rectangulari, in marginem ventralem postice 

 desinente ; latere postico oblique truncato, ad apicem acuto ; 

 umbonibus elevatis, angulatis ; area, cardinali angusta lanceolata; 

 cardo dentibus ad octo utrinque instructus. Long. £ ; alt. T 9 «y ; 

 lat. T V poll. Hab. ? 



