28G MH. E. A SMITH ON THK [A]>r. 1, 



lenuis ; anfrnclus o, coiicexi, microscopice njiiraliter sfriafi, 

 siitiira snJ)j)rofun(la sejitncti ; npertiira ooafa, .sKpenie paulo 

 acuminata, loncjit. iotius h siibrequaiis ; peristoma tenue, 

 continuum, 'inavyine columellari angunte reflexo. 

 Longit. 3g miUim., diam. \f^. 



The spiral striae are so fine that they can only be seen under a com- 

 pound microscope. Under a simj)le lens the surface appears smooth. 

 Couthoiiyia pliciferu, A. Adams, has the aperture more distinctly 

 channelled anteriorly, and the umbilicus defined by a carinate 

 margin. 



DlALA FLSCOPICTA. (Plate XXI. fig. 20.) 



Testa minata, imperforata, conicu, tenuis, uitens, albo-pcllucidci, 

 strigisfuscis longitudinalihus, et zona interrupta lactea ad 

 periplienam picta ; (infract us 5, vix convcxiusculi,2>riini duo 

 spiraliter tcmiitcr striati, cceteri Iceces, uliinms in medio 

 rofundc angulatus ; apertura incdiocriter magna, longitudinis 

 totius ^ vix cequuns ; lahruni tenue; columella recti uscula, 

 lev iter obliqua, antice suheff'usa. 

 Longit. 2q utillim., diain, \\. 



This pretty little shell has the surface smooth, with the exception 

 of the first two whorls, which are finely spirally striated. Tlie 

 upper extremities of the brown stripes do not extend quite to the 

 suture, and on the body-whorl pass between the opaque-white row of 

 dots at the peri[)hery. 



llissoiNA MELLissi. (Plate XXill. fig. 34.) 

 Testa ovuto-turritd, ulha, solidiuscula ; anfractus sex, supremi 

 duo convcxitisculi, spiraliter striati, cceteris superue tabulati 

 et rotundo ungulati, costis calidis circiter 11 (/;/ anfr. 

 ultimo ad basini continuis) instructi, striisque spiralibus 

 tenuissimis sculpt i ; apertura oblique ovata ; lubrum incras- 

 satum, duplex, superne subsinuatuni ; niargo columellaris 

 callo refiexo, superne labro juncto, indutus. 

 Longit. 3 millini., diam. 14. 



This is a strongly costate species, with very tine transverse stria; 

 un and between the ribs. The outer basal margin of the aperture 

 Las a double lip, and the ribs are more or less regularly continuous 

 up the spire. 



ItissoiNA TUKTONi. (Plate XXIII. fig. 35.) 



Testa gracilis, turrita, alba; anfractus 6-7, convexi, sutura 

 obliqua sejuncti, primi duo spiraliter lirati, cceteri costis 

 longitudinalibus 10-12 tenuibus, oblique curvatis, instructi, 

 tratisversini inter castas tenuissinie striati ; apertura obliqua, 

 parca, longit. totius 3 vix cequans, adbasim late effusa ; lab rum 

 mcdiocriter incrassatum, intus longitudinaliter striatum; 

 columella obliqua, parum arcuata. 



Longit. 3 millim., diam, 1. 



The spiral lirse upon the apical whorls are jieculiar, and the ajiex 

 itself is large in i)roj)ortion to the size of the shell. 



