35 



flata, facie variabilis, striis concentricis confertis notata et epidermide 

 rugosa inflecta induta; umbonibus fere medianis, tumentibus, plus 

 minusve prominentibus ; margine ventrali recta vel incurvata; ex- 

 tremitatibus rotundatis ; cicatricibus inconspicuis ; ligamento interno 

 ossicula firmato. Long. 4 -\- ; lat. 1 ; alt. 3 + millim. Inhabits 

 Simon's Bay, in sand, 1 2 fathoms. W. S. 



The hinge is as in K. compacta, but the ossicle at the hinge seems 

 to bring it under Montacuta. In young specimens there is a punctate 

 appearance by transmitted light. Its true place must be decided by 

 the animal. It is very variable in outline. 



MoxTACUTA DiVARiCATA. T. minuta, tenuis, albida, oblique 

 ovato-trigonalis, cuneata, convexiuscula, liris tenuibus interdum bifur- 

 catis radiata ; umbonibus acutis terminahbus ; extrem. postica late 

 truncata ; portione antica semiovah, acute rotundata. Ossiculum antice 

 quadratum, postice triangulare truncatum. Inhabits Hakodadi, on the 

 spines of a Spatangus. W. S. 



This interesting little species is readily distinguished by its very 

 oblique, cuncate form, and radiated surface. 



Cryptodox subradiatus. T. rotundato-elhptica, i^lanata, mar- 

 ginibus rotundatis ; umbonibus angustis prominentibus, medianis ; 

 extus lirulis radiantibus subimpressis margines versus conspicuis 

 disco obsoletis ; lineis incrementi conspicuis remotis fluctuosis ; intus 

 cicatricibus elongatis ; linea palliali interrupta, punctata ; valvae alterse 



dente cardinali subulato, lateralibus subobsoletis ; valvse alterse ? 



Long. 3.75; alt. 3; lat. 2 millim. Inhabits St. Simon's Bay. W. S. 



Only one valve was found. The bands of growth are alternately 

 opaque and diaphanous, and the pallial line is broken into dots as in 

 Lucina proper. 



Cryptodox polygoxius. T. parvula, tenuis, fragilis, lucida, 

 alba, globoso-quadrata, striis incrementi leniter insculpta ; umbonibus 

 medianis eminentibus, tumidis ; extremitate antica acuta ; extrem. 

 postica latiori, oblique truncata, angulo postero-ventrali acuto ; mar- 

 gine ventrali et margine antica continuatim arcuata ; portione postico 

 angulis binis radiato. Long. 4 ; alt. 3.5 ; lat. 3 millim. Inhabits 

 Simon's Bay. Cape Good Hope. W. S. 



It is larger, more ecjual in its diameters, thinner and more angular 

 in front than C. Jiexuosus. 



SciXTiLLA THORACIC A. T. parva, tenuis, lucida, nitida, elongata, 

 tumida, subovalis, minutissime radiatim striata et fasciis concentricis 

 etiam punctis lacteis ornata ; umbonibus antemedianis, minutis ; ex- 

 tremitate antica rotundata ; extrem. postica altiori, oblique subtrun- 

 cata ; limbo tenuissimo ; cicatricibus bene impressis. Long. 13; alt. 

 8 ; lat. 4 millim. Inhabits Ousima. W. S. 



