33 



bosa, postice valde truncata, superne compressa ; declivitate umbonali 

 angulata ; antice rotundata ; umbonibus medianis, tumidis, acutis ; 

 lineis incrementi conspicuis : cavositas cretacea, citrina. Long. 20 ; 

 alt. 17 ; lat. 12 millim. Inhabits Hong Kong harbor. W. S. 



Mysia obliqua. T. parvula, oblique rotundato-ovata, lenticularis, 

 flavescens, zonis incrementi raris ornata ; umbonibus antemedianis ; 

 regione postica latiori, rotundata ; margine ventrali oblique arcuata ; 

 costa interna umbonali tenuissima ; eardine debilissimo. Long. 8 ; 

 alt. 7 ; lat. 3.5 millim. Inhabits Loo Choo. W. S. 



Has no very marked characters, but in general is like a small M. 

 glohularis Lk. It is more globose than M. Jiglina. It is possibly a 

 very small specimen of Diplodonta Koreensis Ad. and Rv. 



Leptox firmatum. T. subtrigona, planata, lactea, subdiaphana, 

 glabra ; umbonibus medianis, hand eminentibus ; margine ventrali 

 fere recta ; pagina interiore subrugosa ; cicatricibus subrotundis ; denti- 

 bus Curtis, validis. Long. 5 -]- ; lat. 2 -f ; alt. 4 millim. Inhabits sand 

 at low water, Simon's Bay. W. S. 



In shape like L. squamosum, but distinguished by its short, stout 

 teeth. The rugosities are probably caused by a perforating parasite. 



Leptox coxcextricum. T. ovato-triangularis, subplana, con- 

 centrice concinne lirata (liris acutis), epidermide subrugosa marginem 

 implicante induta ; umbonibus postmedianis, acutis ; cicatricibus sub- 

 elongatis ; linea pallii e margine remota ; dentibus minimis, laterali- 

 bus utraque valva remotis,fere obsoletis ; valvae dextras dente cardinal! 

 unico ; v. sinistras dentibus duobus minimis margin! contiguis. Long. 

 10; lat. 4 — ; alt. 7-{- millim. Inhabits Sydney harbor. W. S. 



This beautiful species is easily known by its minute teeth, concen- 

 tric sculpture and abundant epidermis. Its shape !s unusually un- 

 symmetrical. It not unlikely belongs to a genus not yet established. 



Leptox lucidum. T. parva, tenuis, nitida, alba, ovato-quadrata, 

 postice dilatata, concentrice striolata et obsolete radiata ; umbonibus 

 medianis acutis tumidis ; margine dorsal! recta ; extremitatibus obliquis, 

 angulis ventralibus acutis rotundatis ; margine ventrali vix arcuata. 

 Long. 9 ; alt. 6 ; lat. 3 millim. Inhabits Hong Kong harbor. W. S. 



Kellia crexulata. T. tenuis, flavescens, trapezoidea, margini- 

 bus plerumque rotundatis ; margine ventrali recta et compressa ; 

 umbonibus fere medianis, prominentibus ; lineis increment! conspicuis ; 

 tota pagina interior! rugulosa, cardinem versus marginibus crenulatis ; 

 dente cardinal! conspicuo, conico, altero celato fossam ligament! 

 metiento ; dente laterali singulo, curto, hand obvio. Long. 9.5 ; alt. 

 6.5 ; lat. 4 -f- millim. Inhabits Hong Kong harbor. W. S. 



Readily known by its crenulated hinge margin. It has the aspect 

 of Scintilla, from which it difiers in its teeth and ligament. Only 

 one valve was found. 



PROCEEDIMGS B, 8. X. H. — VOL. VlII. 3 APRIL. 1861. 



