DR. P. P. CARPENTER ON NEW MOLLUSCA. 



natiSy postice diver gentibus, striis incrementi crebris acutis, 

 aliter hand sculpta ; parte antica t. jun. aperta, adultcK clausa ; 

 clausis tenuissimisy secundum incrementa undulatis t super urn- 

 bones prolongatis, umbilicos postice formantibus ; epidermide 

 fugaciy tenui, pallide viridi. 



Hab. Monterey, Rich. ; Vancouver, Lord j S. Diego, Cooper. 

 = Pholas darwiniiy Sby. 

 = Jouanettia darwiniiy Mus. Cuming. 

 = Parapholas penita, Tryon, Mon. Phol. 



This remarkable shell differs from Jouanettia in having both 

 valves equal; from Pholadidea proper in having no coriaceous 

 cup, its place being supplied by a flattened prolongation from 

 each valve, like a duck's bill in miniature. In Mr. Lord's specimen 

 (preserved in the British Museum), though the valves are closed, the 

 prolongations are widely divergent, as when the bird utters its cheer- 

 ful " quack." The loose, .thin epidermis appears to have covered the 

 bill as well as the valves. Mr. Tryon had probably not seen a speci- 

 men, else he could hardly have affiliated so very 'different a shell to 

 Pholadidea penita. The original specimen is said to have come from 

 Chili. 



DARINA DECLIVIS. 



D. t. tenuissimay planata, elliptica y Machcerceformi, utroque latere 

 hiante ; cinerea, epidermide fortiore induta ; marginibus regu- 

 lariter excurvatis ; umbonibus haud conspicuis, ad duas inter 

 quinque paries longitudinis postice sitis : intus cartilagine 

 spathula elonaata, dorsum versus utraque valva decliviter sita t 

 a ligamento lamina extante tenuissima separata ; dente car- 

 dinali laminato, extante, curtiore ; lateralibus vix conspicuis ; 

 sinu pallii ovali, fere ad medium porrecto. 



Long. 177, lat. -85, alt. -34 poll. 



Hab. Vancouver's Island (Forbes). 



The only other species of Darina known is from the Straits of 

 Maghellan. The northern shell may have been passed over as the 

 young of Machcera patula, to which it bears a strong external re- 

 semblance. 



SAXIDOMUS BREVISIPHONATUS. 



S. t. subovaliy tenuiore, subplanata, albida, epidermide pallide 

 olivacea induta ; iota superficie rugis concentricis t crebris, 

 valde obtusisy et undis incrementi interdum majoribus, ornata ; 

 marginibus subcequaliter excurvatis y maxime ventrali : intus 

 car dine tenuiore y dente antico elongato ; sinu pallii parvo t ad 

 trientem interstitii porrecto, latiore. 

 Long. 2-65, lat. 2'05, alt. M5 poll. 

 Hab. ? Vancouver, ? Japan (Mus. Cuming). 



A very distinct species, in shape and hinge not unlike Callista t but 

 without lunule. It is more rounded and flatter than the three ty- 

 pical California!! species, and known at once by the very small mantle- 

 bend. From four to six blunt riblets are seen on each of the very 



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