165 



Solen strictus. T. valde elongata, marginibus fere parallelis ; 

 rnarg. dorsali lente declivi ; extreuiitate antica oblique trimcatfi ; ex- 

 trem. postica quadratfi, angulis rotundatis ; epidermide nitida, flavido- 

 cornea, linea diagonali inconspicua ; dente terminali ; cavositate 

 incarnata. Long. 4.5 5 alt. 0.7 ; lat. 0.5 poll. Inhabits Hakodadi Bay. 

 W. S. 



General features like S. cornens Lk, but much larger, and propor- 

 tionally more slender. 



Solen gracilis. T. tenuis, gracilis, valde elongata, subcylin- 

 drica, vix arcuata, epidermide flavo-virescente nitida induta ; margini- 

 bus parallelis ; extrem. anticali oblique truncata, sulco subterminali 

 fere obsoleto ; extrem. posticali oblique antrorsum truncata, angulis 

 rotundatis ; dente cardinali terminali, in utraque valva singulo. Long. 

 4.5 ; alt. 0.6 ; lat. 0.4 poll. Inhabits Hakodadi, on sandy beaches. 



w. s. 



The nearly straight, proportionally slender form, and very oblique 

 anterior truncation' afford obvious characters. 



Mach^era sodalis. T. fragilis, compressa, elongato-ovata, pur- 

 purascens, epidermide tenui fusco-cornea induta ; umbonibus ad quad- 

 rantem anteriorem sitis, conspicuis, acutis; extrcmitate antica late 

 rotundata, retrorsum sensim angustata ; pagina interiori purpuras- 

 cente ; costa cardinali alba antrorsum inclinata et inflecta. Long. 

 32 ; lat. 7 ; alt. 22 millim. Inhabits Hakodadi Bay. W. S. 



Greatly resembles M. costata Say. It has a more purplish hue, a 

 more shining epidermis ; but the principal difference is in the pos- 

 terior acumination, and the gentle sweep as well as inclination for- 

 wards of the internal rib. 



Solemya pusilla. T. fragilis, oblongo-ovalis, vix retrorsum 

 dilatata, epidermide tenui pallida sub lente striis confertis radiantibus 

 insculpta, et radiis fuscis remotis picta ; extremitatibus rotundatis ; 

 margine dorsali recta ; margine ventrali leniter arcuata ; umbonibus 

 ad quadrantem anteriorem positis. Long. 1 2 ; alt. 5 millim. Inhabits 

 Hakodadi Bay in 5 fathoms, muddy bottom. W. S. 



Described from a single, perhaps immature specimen. It is near to 

 S. velum Say, though the dorsal margin appears more straight; and 

 if the radiating stria? are constant, it would be a good distinctive 

 character. 



Psammobia spatulata. T. tenuis, compressa, oblongo-ovata 

 retrorsum angustata et ad extremitatem truncata, antice rotundata ; 

 margine dorsali recta ; marg. ventrali arcuata ; umbonibus ad trientem 

 posteriorem locatis, minutis ; callo ligamentali elevato, intus suffulto ; 

 disco striis concentricis exilibus et striis radiantibus teuuioribus in- 

 sculpto : color rufescens, lineis saturatioribus radiata, intus hepatica : 



